Batteries wrote...
I facepalm when I read when people call Kaidan whiny/boring, but everyone is going to have what they like. I see plenty of women that call him Carth clone/whiny/emo/gay too. Maybe they're just more into the more outspoken bad boy type characters.
The most popular romantic interest for Dragon Age gets a lot of flak and he's a gentle soul like Kaidan is. Some guys can't really see his appeal, but I've seen a few of them change their minds when they follow along on his fan thread and agree to give him a chance. The biggest female supporter for a different male love interest has a nasty habit of shooting down Alistair in order to build up her preferred love interest. (The most interesting part is that both male love interests were written by the
same writer.) I think some of the bashing that Kaidan gets is mostly to get a reaction out of others or build up their own love interests. Kaidan is guaranteed to come back in ME3. The ME2 love interests ... who knows? I can understand why they'd want to bash down Kaidan in order to "convince" the developers to spend more energy on the ME2 ones instead.
Personally when ME3 comes out and all is finally revealed, I would not be surprised to see a few "I dumped him because of Horizon, omg" fans quietly redo some of their games so they can reunite with him in ME3 despite their public protesting. It'll be interesting when Bioware starts promoting ME3 in stages with reveal of new crew members. The gloves will really come off then because it's the point of no-return for all love interests. =p
Here's one of the screenshots I like with Kaidan. We just got out of the mako and the third party member was out of sight so it looked like it was just the two of them just appreciating the moment.