From umps to manager to players is there any major sport with more prima donnas than MLB?
I don't know about refs and coaches, but I don't think that the NBA players take a back seat in the prima donna department. I've never seen one yet who didn't make a "who me?" face when called for a foul. And the taunting and trash talk in both the NBA and the NFL are pretty close to the opposite of the sportsmanship that teach game is supposed to further.