Why is this movie causing so much controversy?

I have to admit I believe Michelle Williams is highly underrated as an actress. I know, I know, she was in the teen drama Dawson's Creek. But that show just proved how much she worked after it to prove to the world how much of a talented actress she really was when she broke out of the teen drama and found solid work in adult material. Take a look at her range, such as the housewife of Heath Ledger in Brokeback Mountain dealing with her husband's interest in men. Or her doomed portrayal of a wife haunting the dreams of her husband in Shutter Island. Now let's look at Ryan Gosling. Ryan has been in the game for a while. He will be remembered in one of the most loved romantic movies ever, The Notebook. But don't label him a rom com kinda guy. The guy can act. He was nominated for an Oscar for his work in Half Nelson where he played a drug addicted teacher. Or look at his portrayal of a man believing a blow up doll was his real girlfriend in order to compensate with dealing with the real world, in Lars and the Real Girl. So why am I talking about these two actors? Well both are them are staring in the new movie, "Blue Valentine." The story follows Dean (Gosling) and Cindy (Williams) whose relationship is starting to fall apart. With the balance of life expectations, work, looking after their daughter their marriage is slowly crumbling around them. What happens next is what is shocking the cinema going public. To save their relationship they decide to spend one night in a hotel, where they will try to save their marriage and remember the passion they both felt before all of life's pressures started hurting this couple. In America, there have been many reports that the film has been edited and edited again, due to this one scene, which apparently pushes the limits of the film. Are movie going public still prudes when it comes to this subject? Or is it just good publicity for this small independent feature? Let's just not hope that this movie is all about this one scene, but indeed lets these two actors shine in roles I am quite sure they are both very capable of.  Blue Valentine opens December 26 (Australia)