I wouldn't say he is an idiot. Some people have called him one of the best players in the world and a great reader of other players. But his arrogant a$$hole personality is why I hate him and love to watch him lose.
If he were that great of a player and/or a reader, we'd see him at more televised tables. After all, someone who could read people as well as he proclaims he can should be able to clean up at tourneys.
His self-delusion, arrogance, and cr*p mouth therefore make him an idiot, in my book.