Probably because most of it is very male-oriented and degrading to women.

I mean sure, *some* girls may get off on that, but I can't even watch that shit most of the times. And faking an orgasm really is a turn-off for me. Most of the men in porn are a bunch of lames who wouldn't know how to get a girl off if their lives depended on it. Then you have the asshole wife-beater types determined to make the experience as uncomfortable for them as possible. It annoys the fuck out of me.