I have not liked Calipari for a long time, however, I never thought that he had a problem in being a leader to his team. However, that changed when he threw Rose under the bus after the championship game. Either Cal told him to foul and Rose didn't (I know, it is an incredibly tough task to carry out), or Cal made a coaching mistake, risked letting Chalmers get the shot off and then blamed his poor coaching decision on a player he knew would not be back the next season.
If the latter is true, then he is not only a poor leader, he is also a coach who went brain dead at the decisive moment.