People in the US don't go to movies to watch real violence. There's no actual war footage in most war movies, even though it's readily available. Audiences like indulging in a fantasy of violence, but we don't really glorify real violence.
I'm not completely sure. I think the idea is that violence is inherently destructive whereas nudity is not. Probably using sex as entertainment is more socially acceptable than enjoying violence, even fake violence. shrugs
