Fair enough. I'd say getting defensive over other people's opinions is unhealthy to say the least, but whatever suits you. Though I would contest that Enterprise gets the most hate. I would encourage you not to use "them" as a collective whole to describe people who don't like Voyager as much as you do though, as if something was wrong with that. Ask a dozen people their opinion, you'll get at least thirteen different answers, so best to take em one at a time.
But to your previous queries... Denara, the problem with making her a reoccurring character is the same with any reoccurring race in Voyager, they're destined to be left behind. Pel did appear briefly in Resolutions to solve the problem of the week though. They went out of their way to make her a non-evil Viidian which is great, but never really demonstrated why she was different or why she put up with the rest of the homicidal maniacs. Maybe if she stuck around for a couple more episodes they could've fleshed her, and the Viidian culture out more but as written she just was a romantic interest for the Doctor.
I liked the Vaskans and Kyrians in Living Witness. While they weren't fleshed out themselves, the social conflict between the two races was. You really don't have to know much about either race in this one shot episode to get a grasp of the conflict and how history can easily be revisionist over the years.
Now, if you'll take me separately from a collective group of "them" and address me as an individual, yes I do find Voyager disappointing. I am critical of it's flaws. No, I don't hate Voyager. If I did, I'd spend my time somewhere else posting. To me Voyager was average in it's own right. It's my third favorite series of the five. I still find it the most disappointing of all of them, not because it's terribly bad, but because it could've been so much more in my opinion. All the parts were there, they were just never executed.
If it's your favorite show, that's great and I wouldn't presume to take away from that. But it is a bit silly to get so defensive over others opinions of it, especially when you're taking the same labels that get you in that state and apply them to the other series as some sort of rebuttal. It's a discussion board after all, that's part of the fun debating the various episodes, characters and issues of them with other people. If everyone agreed, what's the point?