Is it the hair?

So out of curiosity, I've ventured around at some Doctor Who forums. Okay, one. But still, there is something I have noticed:

Everyone seems to hate River Song.

I... don't really understand why. Is it another instance of fandom not liking female characters? Is it that people think comes too close for comfort to being like The Doctor? But then, what about Jack? Is it the hair?

I'm seriously curious about that,and not involved in the fandom so I don't really know why.

(Spoilers are Free For All in the comments. Just as a warning.)