Is incest not a big deal anymore?

I realize I'm American. I realize we're seen as prude and ignorant when it comes to cinema. I love foreign films because I don't like being held back by what some producer thinks is appropriate or not.

Have seen more French cinema than the "Average Joe" so I know that nudity is nothing to be astonished at on the big screen. But incest? Why was this treated so nonchalantly? People don't even seem to think it's a big deal. No one has touched upon the very obvious incestuous situation that goes on in this movie.

Did I miss the memo that in Europe incest truly is okay?