[gamechangr]

Because buying a movie or a game is much more intentional in the sense that it appeals to a specific demographic that has opted in (my grandma would HATE Half Life or any most rated R movies, but is way less offended by a sexual reference in a sitcom).

Mainstream Media doesn't want it, enter Showtime and HBO.

I watch movies and play games that I wouldn't want my six year old to be exposed to when he was flipping the channels? Like Leonidas in 300. My kid would have nightmares for days!!!

[undrcvr-lagggal]

I expected a response like this but didn't cover it in the question due to lack of space. However, even on Showtime and HBO there aren't uncensored depictions of sexual acts or full nudity. Yet there is plenty of violence intended to look realistic. I'd expect that if our society accepted uncensored sexuality in movies, there'd be sitcoms with it too, since that's already one of their main topics.