Here's how name-calling works.
Now, at this point, Guy is faced with being labeled by some retarded chick. Guy immediately leaps to defend his honor, claiming that he isn't sexist or what he said wasn't sexist. This allows Girl to divert the discussion from the topic of nerdy girls have a proclivity to craziness and instead on Guy's personal character. She has successfully silenced his opinion.Guy: This nerdy girl I once dated was a fucking headcase. It's been my experience with a lot of gamer girls, actually.
Girl: That's sexist.
On the other hand, if Guy does not bother to defend himself and instead attempts to maintain the current conversation, Girl can point to his posts and demonstrate that he's a sexist. Being surrounded by people who have been indoctrinated into a politically-correct environment, they will dismiss Guy's claims as being invalid because they are typical of a chauvinist. Girl has successfully silenced Guy's opinion yet again.
And this behavior happens all the fucking time, especially around here. So cut that shit out.