Just because there are uncomfortable shocks and very raw hypocrisies doesn't mean they remove our humanity or are put there by a filmmaker to attack that humanity. There are very real sympathies given to these characters. If he didn't portray them right, *say that*. Not some other thing.
The fact that there's an obese black girl playing the main character for a while is not there to make us laugh - with the exception of one line I could MAYBE see that way, if we laugh it's because of we're jerks. Own up.
Because the story is delivered like a picture book or a music box, not a shock jock's routine, and when the main character hears that all of life is hopelessly written backwards and forwards she gives the messenger a look that says 'Even if you're right, you're full of shit.'
And seeing as the protagonist is unscathed in the end, universally willing to make connections, sympathetic even of the world's freaks, you should probably be open to a little of the same.
Yeah, I know, no one knows what I'm talking about. XD