DevilEyes, I dunno Buffy is pretty much one of the few female characters I find actively annoying, I think it's less about gender than SMG's portrayal of her.
I don't have a problem with people being annoyed by characters I love, people have different tastes. It's when they characterize them inaccurately, like calling Buffy "whiny" which makes no sense. (Unless you're Cordelia desperately trying to convince herself that she's superior to Buffy - which is where the original "WhinyCryBuffy" comes from - despite the fact that she spent most of her time on BtS having her ass saved by Buffy while complaining - whining, you may say - that her life had become so awful since Buffy moved to town.) When you call "whiny" I would expect it to be someone who has no real problems in their life and nothing really bad happened to them, but they keep complaining about just about anything.
As for the way that gender comes into it, well, I've never seen any of the angsty male heroes who had bad things happen to them called "whiny". Oh look that Whiny Cry Sisko, his wife got killed, boo hoo! Look at that Odo with his identity issues, what a whiner! That whiny Batman, still hung up on his parents' death!