It isn't a show that is pitched as "for lesbians about lesbians", it's a camp, cult classic where over-the-top storylines and ridiculous plots are the norm. Shell dressed as an enormous penis, for example
Or maybe the writers did the clever thing of rewarding the viewers from the start by having a happy, successful lesbian couple run off into the sunset together. After that, perhaps we'll put up with almost anything...
I think you've pretty much hit the nail on the head with both of those comments, Candleshoe. Being such a dramatic, sometimes hardcore show, it's almost as if the fact that something bad is happening to a lesbian couple gets pushed aside, because of the conditions and other circumstances. Shaz, for example. Tragic, and could totally be viewed and just another victim of The Cliche, but she wasn't the only one targeted. A lot of bad crap happened when half of Larkhall exploded, and so maybe it didn't feel like they were just targeting the cute lesbian couple? I dunno, i could just be talking an enormous amount of crap, given the fact that it's 2:20am, but Bad Girls always makes me vocal.
Also, the show has it's moments, like you pointed out, where it really doesn't take itself seriously. Shell and her rather large friend is a prime example of that. It's not all about the lesbian love/angst stories, there's a lot more going on, funny, serious, they've even had a couple of straight storylines!

Plus, their characters remained consistant throughout the show, which is more than i can say for L Word and it's 180-wonders. Yep, that was an out of nowhere dig, i'm bitter about the last season.

Anyway, enough of my incoherent rambling i think. I don't view it as part of The Cliche, while all common sense tells me i should, and i think the Nikki/Helen relationship is a huge part of that. They got their happy ending. I can't think of many other TV lesbians that got to walk off into the sunset together.
~ Jen