As you said, we'll have to agree to disagree on the structural thing... but I want to respond to one point...
You're kidding about Dallas and Melrose Place, right? That shit got complicated FAST.
You had to pretty much watch every episode to understand what was going on but the writers told their story in a relatively linear straightforward manner--there weren't out of order flashbacks, multi-perspectives on the same event, every storyline connected, they weren't nearly as densely plotted where events were constantly being re-examined because of more and more layers piled upon giving new context to what was previously believed. They had a few parallel-running storylines that were resolved by the end of the season and the series could theoretically go on in definitely. The writers didn't have to worry about putting things off for years at a time. The writers didn't rack up dozens or even hundreds of unanswered questions leaving the audience constantly confused. The episodes picked up right where they left off the previous week instead of jumping around all the time--telegraphing what was coming then working its way back to filling in the gaps. The scenes weren't nearly as rapid-fire--you could actually follow what was going on as the episode unfolded.
They didn't run one hour long recap episodes every few months and the episode recap at the start of each hour weren't as complicated. You didn't need to check with Wikipedia to keep things straight. The writers had assembled the story for you so you didn't have to stop and put the flashbacks in order or remember who knew what when, you didn't have to fill in the blanks because the episodes weren't so crammed full of stuff that a lot of things were left for you to fill in. There wasn't a need to keep everything cloaked in a constant of mystery.
It's soap, the twists and turns, complicated relationships... one could argue, the complicated mythology (yeah, not scifi mythology, but mythology none the same) could be intimidating. But the writing--as cheesy as it might be at times-- was strong.
Well those shows I mentioned had season long arcs and weren't necessarily about a Big Picture mystery the way LOST and other shows like it were. Dallas was about a wealthy oil family in Dallas--pretty simple premise. MP--twentysomethings sharing life struggles in an LA apartment complex. The writers could then--which they did--craft season long arcs without concern to a bigger picture. Can you seriously tell me that LOST and Dallas--subject matter aside--are even the side beast in terms of structure. LOST was all about interconnected mysteries on an island that required stall tactics to prevent moving the story to fdar ahead and ruining other things linked. I never once experienced the kind of frustration and confusion as I did with LOST and its brethren. I didn't have to zoom in or screencap on an image and pick it apart trying to find meaning the writers suggested was there only to later learn the writers were full of shit.
But as a matter of preference I prefer that more modest serialized format. I'd rather focus consistently on 7 or so main characters, 2 or three linear plotlines with only a few mysteries/questions that are resolved definitively by the end of each season rather than some plot-heavy mythologically laden behemoth that is structured in an unnecessarily complicated way that guts the opportunity for longer scenes, more one-on-one character time--Everything on LOSTesque shows is rushed, abbreviated, plot heavy reducing characters to exposition dumpers. I just don't find it a very rewarding experience. I sit down to enjoy tv not feel like it is a huge undertaking the way LOST was.
re:the relationships weren't really that complicated on the shows I mentioned--the writers would usually pare off the ensemble in groups and keep them together over a series of episodes. LOST and its ilk almost each week tried out various pairings then spin them off with others and do that over and over again. Same thing for S1 of Heroes.