You began by calling yourself a "French guy", which means you do see the movie for what it is, a very good story about this phenomenon.

It's also true that it isn't only conservatives who criticise it, it is all those who have no power of abstraction or cultural experience to understand it. That isn't a crime, but it is the equivalent of yelling at people speaking a foreign language at the mall.

As I said elsewhere, people who have a limited concept of the world outside their country can not understand the main point of the movie: the conflict between her religious education and the pull of seeing her peers dancing and having fun. Of course they had to show the dances as they really are, in order for the story to work.