I'm finding this discussion a bit odd.
DS9 is fairly opimistic. To show the character's progression
Sisko moves into Godhood
Bashir moved from 'slow' child to prodigy and worked through his idiocy in the early seasons by growing.
Dax died and was resurrected
Kira went from her racist views of the Cardassians to helping them
Garak went from Exile to helping his people
Odo went from being lost to going home
And on the list goes.
The setting might be darker but the optimism in the show is bright as any other trek show. As Sisko says "it's easy to be a saint in paradise", DS9 shows that even in the face of despair, humanity (and others) rises above and grows rather than wallowing and giving up. And to me this is a much greater display of optimism than anywhere else in canon.
Sure it may not have the 'family' of TNG, but the characters of DS9 are more complete as strong individuals and family, while an argument could be made that TNG's characters are more flawed as epitomised in Riker who shows little aspiration to help his career but rather to play it safe (second fiddle to Picard) and almost that it's acceptable to stagnate as a person rather than to try to grow as a person (as I believe is outlined in one of Picard's speaches). But I don't think I really want to open said argument.
As for the shows, I do think DS9 is a stronger show, the continuity is greater, the plot is a larger one as it all seems to build towards something. (Rather than episodic TV in TNG). But also DS9 manages to also do episodic TV incredibly well (much better than B5) while still keeping the main arc going. You can basically grab any episode, enjoy it as a single episode as well as how it fits into the greater picture. And for me that just makes it much better than TNG.
I think I will comment on your post.
You do have some valid reasons there for liking the show. However, I will begin with mentioning the primary reasons I disliked the show myself (and then perhaps comment on some parts of your post).
Now I have to think back as to why DS9 rubbed me the wrong way, and I did pretty much see every episode of it, although some I don't remember that well anymore.
I basically grew up on TNG. And to be honest, I didn't even like the main characters in it at first. The 2 parts of the show that hooked me on it were:
1. Data
2. The Enterprise D herself.
I remember when I first started watching the show, and how the character of Data was so well portrayed by Brent Spiner. You basically have an android here, a machine, but so childlike and innocent about life that you just couldn't help to like him. I could write an essay on why I like the character, but he's pretty much my favorite Trek character.
As for the Enterprise D, this is *exactly* how I pictured a futuristic Starship would look like. If you notice pretty much in all other sci-fi, Ships are portrayed as these gritty machines with wiring, piping, and other appendages basically running thru the outside of it. Star Wars is infamous for this. (The X-Wings looks like these giant pitchforks with engines, and the Millenium Falcon looks like one of those "Forkspoons" you might find as part of your KFC meal, and Star Destroyers look like big slabs of cheese). It's either that, or ships that looks way too organic and insect like, or ships that look like huge boxes with engines (Think B5's "Agammemnon"), and I don't hate all these designs. I think the Millenium Falcon is a great looking ship, and the Agammemnon certainly looks like what the first Space Vessel constructed by humanity might look like, which is all fine and dandy.
The Enterprise D to me however looks like something that humanity might design after they have been in space for centuries and are starting to perfect space travel (Sort of like the difference between an F4U Corsair and an F22 Raptor).
TNG also had the advantage in my mind that it was a far more realistic attempt at showing us what space exploration might be like in that time, and most of my favorite episodes tend to be the exploratory ones (like "Where no one has gone before" or "Remember Me")
Just on those 3 things, TNG already beat out every other Trek series in my mind, and beat out almost every other Sci-Fi show relating to Space. Now I'll make a quick comment about TOS, since I know some might jump in and say that TOS did better with Space Exploration.
Personally I like TOS, but for different reasons. TOS is really more made in a format similar to Horatio Hornblower, and the same type of sea adventures but set in space. TOS had it's share of great exploratory episodes. In my mind what hurts it the most is the campy approach it takes to some of these tales. Example "Who mourns for Adonais" is a great episode that I enjoy watching, but it's such a campy attack on religion that it's almost laughable (Giant Greek Gods in space, that can, no doubt be defeated by finding their weaknesses, usually a power source of some sort). I enjoy the episode on it's own campy merit.
Anyway, on to DS9. I think the main reason I dislike the show is that it portrays the Star Trek Universe in such an antiTNG fashion. I know most people like that, but to me, TNG is the Oasis in a desert of bad character melodrama.
I mean pretty much every show on TV relies on character interaction, and usually they try to make their characters flawed in some way as to base stories on and make them interesting.
TNG on the other hand, strived to show us characters with very few flaws, and that forced the writers to concentrate on other aspects of the show that I enjoyed more (like the science oriented stuff)
To me, watching DS9 is like I'm watching any other show on TV. Personally if I watched Star Trek because I want to see Riker be insubordinate to Picard, or Troi be a bitter malcontent, or Crusher be some flirty bimbo, I can watch almost any other show on TV. Any flavour of Law & Order, or NYPD Blue, or The OC, etc etc. I prefer to watch characters working together harmoniously to overcome some external factor, and TNG has that in spades.
I think that would have to be my primary reason.
Secondary reason I think is the fact that I never found any of the characters in DS9 likeable.
Sisko came off as being a complete asshole. How can he have the nerve to verbally abuse Picard and blame him for the attack at Wolf 359? (I *hated* the fact that Picard said nothing to that). Like it's Picard's fault that he got kidnapped and assimilated into the collective. I don't know how much it was about the way Avery Brooks portrayed the character, but Sisko just wasn't a likeable person to me, and he never changed.
And of course, Kira. Hmm. Ok, I understand that she's pissed at the Cardassians, and I understand that she's pissed at the Federation for butting their heads into their matters. Was it necessary for her to be a complete bitch all the time? And her transformation from hating Cardassians to working with them never seemed realistic to me. One day she wants to kill Dukat, the next day she's working side by side with him. Right.
Jadzia was probably the most annoying character to me. She always carried this air of superiority to everyone. I can't really put my finger on exactly what part of her smugness annoyed me the most. I know Bashir was always after her, and that one episode where Bashir's fantasies came "true" (with the fake Jadzia that liked him back) and the real Jadzia finds out and says something like "Oh no Bashir, this was your private fantasy and we shouldn't have been made aware of it" just reeked of that smugness, in a way saying "yeah I know you're an imbecil, but since I'm so much better than you I'll forgive you for it".
Speaking of Bashir, his whole character arc was "Hey I'm an incompetent person, hey wait a minute? I'm genetically engineered? cool! *sits back and scratches balls for the whole series*)
Odo had the potential to be a likeable character, but what the hell, his main nemesis is......Quark? That's like Superman's main enemy being the 16 year old kid that wanted him to toss the nuclear missiles into the sun for the entire movie. His real nemesis should have been Garak. I remember the episode when Garak tortures Odo for information about his race (I think that's what it was) and Odo ends up caving in and gives it to him.
Hmm, ok, so Odo got put into a bind where his advantage was neutralized. Fine. Preferably Odo should have died without divulging a damn thing to him. But since he did end up caving in like that, believe me, the second Garak would have loosened his grip on Odo's weakness, Odo should have grabbed that fucker by his nuts and squeezed them 'till his eyes popped out of their sockets. But no!! we get Odo retreating like a little bitch and Garak "sorry he had to do things like that" (yeah I'm sure he was so sorry)
And Garak, well, he was just sooooooooo smart compared to everyone else!! He could fool just about anyone on that station with his scams. Sisko giving him one punch in the face wasn't enough. Seriously, some of the DS9 residents should have cornered him with 2x4's and given this piece of shit the beating of his life.
Really I could keep going. The only characters I kinda liked in DS9 were Martok, O'Brien (who was a TNG character to begin with anyway), and occasionally Bashir had his moments (like when he fell in love with that autistic genetically enhanced girl, or when he tried saving that Gamma Quadrant race from the plague inflicted upon them by the Dominion.). Everyone else really was a dick.
Well, then there's a bunch of other minor details that I hated about the series. I hated that the Federation was so weak that it couldn't provide the help the Bajorans needed (Really the only reason they even butted into the matter was because of the precious wormhole) and it took a war to get the Federation out of it's bean couch to do something.
I hated the alien makeup as I never found any of it believable (All trek suffers from this, so it's not a DS9 specific problem, BUT DS9 is the worst offender for it since it was for the most part an alien centered show)
I hated the whole concept of a war. I'm not stupid. Right away I could tell the "war" was a crutch to get the series out of the stagnant rut it was falling into as other shows have done in the past. I hated the fact that the whole war was based on WWII concepts that would never work in a universe with access to 24th Century technology. Section 31 was a lame attempt at creating some type of secret Federation organization that played "dirty" to win. The concept was fine, but it just came out of left field.
I hated the whole soap operatish feel of the entire series. Everyone spends at least 5mins an episode "lovingly staring into each other's eyes" (Something Smallville would mimic 10 years afterward, at least Smallville had a better excuse for it).
Odo sides with the solids solely because he loves Kira (which not for a second was written believably). It's clear Kira has no interest in him anyway, I'm not sure what the explanation was for her to get into a relationship with him anyway. The female founder sleeps with Odo in a "solids" type way (so they can't form a detailed face, but they can form complex genitalia AND they can form the necessary nerve structure to feel that kind of pleasure? And to add insult to injury, after their "session" the female founder says something along the lines of "this wasn't bad, but it doesn't even compare to being joined to the link". I almost busted my sides laughing at that.
Really I could keep going, but I'm getting tired. Suffice it to say, every series had some serious problems. TNG thankfully didn't carry it's problems into other good episodes (most of the time). DS9 is the only Trek series with so many of these things that I hate in it, and it's almost unwatchable to me.