Funny, I actually caught this movie on TV last one night while staying in a hotel. It was some special pre-screen viewing on, maybe HBO? I forget the channel, but something along those lines.
It was interesting to watch. It does tackle some points about rudeness and selfishness in the US (which I think is applicable in any country, but hey, what do I know?), though it's nothing remarkably thought-provoking. The main characters, the young girl and the old man, were interesting enough for me to stay invested in their personalities and the overall story.
The movie does have a tendency to get extremely self-righteous and up its ass at times, though. Some of the rants of both characters essentially boil down to "BTW ANYONE WHO DISAGREES WITH ME IS FUCKING EVIL AND A MORON," and that's also shown blatantly in their actions. But I don't think it's meant to be taken extremely seriously. It's a mildly clever satire, nothing more, to be honest.
It'll probably cater to people who can't wait to demonize America in every aspect, but those people are probably just as guilty as the ones the movie targets.