Guys can be complete assholes too, though. I'm not like, saying this to you personally, but girls put each other down a lot. We're all too eager to say "All girls are mean and backstabbing I'm only friends with guys!" Also, theundeadhero is right.
I dunno how to comment on what you said in general since I don't have that much experience with life or anything, but I know for me, having self-confidence isn't all that important. I mean, I don't want someone who's constantly putting themself down, but being insecure or shy or whatever isn't going to make me walk away. That's dumb.