What do people write about when their PMSing?

I'm wondering if the last scene of the utterly depressing movie Mammoth was intended to be funny. After her nanny moves back to the Philippines upon hearing news of her son being molested, Michelle Williams cuddles with her husband who just cheated on her with a Thai hooker and says, "We're going to need to find another nanny." At this point I crack up and think to myself, "Wow, Moodysson must be making some really striking commentary on how vapid Americans are with their globalization and their fancy SoHo studios." Instead, I am surprised when the end credits roll and "The Greatest" by Cat Power starts to play. What the fuck? So am I actually supposed to feel bad? Sure, these people are confused and knee-deep in white guilt, but does this mean I should mourn for their mediocrity? Moodysson has apparently stated that he is too old to judge others, so I am supposing he purposefully did not want to moralize his own story. I respect that, let your audience do the thinking. Still, the soundtrack clearly strived to leave at least a little bit of feeling in the viewer. Maybe the problem is that this is a movie about a young family in New York City and the person who wrote it is an old dude from Sweden. He's not too hip with the American music. Apparently he loves Ladytron, though.