The desire to see women utterly degraded and powerless explains in part why anal sex has become so popular in porn. In the real world this act is becoming more common, but I doubt that many women are seeking out the type of anal sex that the pornographers depict. What generally makes anal sex so appealing in porn is the potential pain and harm that robotic and mechanistic thrusting can cause women.
One porn executive explains why users like anal: “Essentially it comes from [every man] who’s unhappily married, and he looked at his wife who just nagged at him about this or that or whatnot, and he says, `I’d like to fuck you in the ass.’ He’s angry at her, right? And he can’t, so he would rather watch some girl taking it up the ass and fantasize at that point he’s doing whatever girl happened to be mean to him that particular day.” Similarly, one producer at the Expo told me that he was specializing in anal-themed movies because “men like to see just how far the women will go with the cocks up her ass. I like to see them pushed to the edge, so I make films I like to watch.
Gail Dines, Pornland: How Porn Has Hijacked Our Sexuality (found here)