I haven't read all of this thread (because it's 8 pages and I'm lazy), but I'm on the "it's the culture in which the game was made" side. I think six and nudity can/could be handled well in games, but whether it will be received well by institutions like the rating board is a whole different matter. As it is, six and sixuality has always been represented in ES somewhere (and fairly well I think), so I'm not too fussed by it.
You can see how different places view six and stuff a bit in films I think - a film like The Sweetest Thing was rated 11 in Denmark, 15 in the UK, and R (which I think means you should be over 17) in USA.
Interesting to note maybe, but I think the last time I saw complete nudity in a game, it was when I was looking at brutally beaten dead women in LA Noire.
The last time I saw complete nudity in a game, it was Daggerfall. I did not find it disturbing or titillating. Not sure how I'm going to feel about heads rolling around--though I suspect "horrified" might enter in there somewhere. Won't stop me from buying the game, but do feel that morals are twisted here.