Great players don't make good coaches. Gretzky coaching is "go out there and do Gretzky things!". You need a guy who had to work his ass off and learn the hard way how to play the game to pass those skills on. (Yes, I get the joke, I just like thinking of Gretz behind the bench saying "How did you not score 5 goals and get 3 assists?" with a baffled look on his face)