Because when a movie is considered by many to be the best movie ever, at the end I should feel myself emotionally captured, with either tears in my eyes or a pain in my stomach or both, as a minimum. None of these events occurred after watching CK, though. When I saw the Rosebud word melting away and the No trespassing sign at the very end, I just thought, ok, it was a good movie. Outstanding technique, by the contemporary standards. It left me emotionally cold and distant. I don't know, probably it's me....