I was a Cloudmaker lurker, and I have to say that that was an amazing experience. As to the OP, I agree 100%. Very well put.
I really loathe the argument “if you didn’t like it, you must not have understood it,” but I have to say that most of the people I know personally who hated the movie thought that they were aliens at the end, which would completely change the ending. Too bad. And, yes, I realize that you can still hate the movie even after understanding the ending.