Over time, it's easy to focus on the flaws, and forget the good points. Sure, the show was flawed... Sure, it could have been better. But then everything is. There is no show that's ever been made that always got everything right. It's just not possible to be perfect (or please everyone, for that matter)... But the bottom line is, despite the flaws, it was ambitious, it was groundbreaking, and for the most part, it was good. At its best, it was simply amazing.
It really did some new things that you'd never seen before. There's the whole arc thing, for one... Having character arcs is not really anything new, characters evolve in every show. But extending that to the plot and building a show that took three or more seasons from foreshadowing to set-up to pay-off was new. Other shows have imitated it, and in fact pretty much every SF show now has arcs lasting a season or so, and sometimes things set up a little longer than that, but never as relentlessly as B5 did. No other show has ever had the depth, the conceptual texture, or the scope that B5 had -- it took full advantage of the genre, and had moments that just took your breath away.
To compare apples and oranges, take Buffy. Buffy is perhaps the pinnacle of "tactical" success. Buffy was polished and smooth and relentlessly entertaining. And, at times, it produced some unabashedly "wow" moments. B5, on the other hand, wasn't as polished and smooth, but it had infinitely more scope and depth, more "strategic." Of course, that's not Buffy's fault, it was limited by its genre, and honestly, I think Joss Whedon was playing to his considerable skills, just as JMS was to his. But B5 wasn't Horatio Hornblower in space (Star Trek) or the Hidden Fortress meets Battle of Britain (Star Wars) or a Western in Space (what I hear Firefly is... I'll be watching it soon). It was something bigger, more epic... In short, it was something more. Did it pull it off? Mostly. Was it better than Buffy? Apples and oranges, but I'd say no -- there really hasn't been anything better than Buffy yet. But -- while Buffy produced its share of "wow" moments, it never produced the "holy shit, that is fucking amazing" moments that B5 produced at it's very best.
In hindsight, it's easy to see how I got addicted to B5. You could always tell big things were coming, and they did, and then even bigger things came. Countless times it surprised you. You were always hanging on what would happen next, how this or that thread would work out. Apparently, so were the cast and crew -- hearsay has it that this is one of the rare shows where everyone would read the scripts the moment they got them to find out what was going to happen next. Of course, after season 3, and especially after season 4, so many big things had happened that there was no way to top them, and it descended from the best of epic space opera to more of a humdrum soap opera... So, it's easy to see how I lost interest in it, as well. JMS has always called B5 a "novel for television," but as I've said before, if this had been a 500 page novel, I'd have thrown it against the wall and cursed the author for putting the biggest climax at page 300.
But then, no TV series has ever ended well. I considered seasons six and seven of Buffy moderately painful, and the less said about season seven of STTNG, the better. Hell, damned few novels pull off a good ending, and there's a lot more opportunity to plan those out. Endings are just plain hard, I guess.
But why was B5 so cool? Just one example: the words "I am called Valen" took three seasons to set up, were completely surprising, and yet caused a whole lot of things to suddenly make sense.
I'm still disappointed the spin-offs never took off, flaws and all. But, oh, well, it saves me from buying more DVDs, and gives me more time to reminisce about was was.