Actually I think the her being on her period might have been a symbolic thing actually since the period signifies the end of a cycle and the beginning of a new one, and well, that's the last time they're intimate, if I remember, and after that Jaime starts subverting a lot of the shit she tries to pull. But it's entirely possible that GRRM thinks period sex is icky.

But you're right about a lot of the gender divide. I had a friend who fast forwarded it because she was so disturbed by it, and I felt sick to my stomach (though I still watched it twice because I was like, There's no way this is how it went down.). If they wanted to show her enjoying it, I mean they've shot scenes where women enjoy sex before so it's not like they don't know how. Hell there was a scene like that in that very episode, which I enjoyed very much! I doubt it'll get addressed, though, because they're not going to make Jaime hate himself for the rest of his life and they obviously think they did an outstanding job shooting that scene, so it just kind of puts a damper on the show for me right now. They just really dropped the ball and I think actively hurt some of their fanbase (as in, emotionally hurt) so I guess we'll see what happens.

Rape (or the threat of rape) as a plot device or aid for character development really needs to stop though.