Reading between the lines, listening to the press conferences, all the interviews Fleck repeatedly brings up the leadership angle. Right now he feels he needs a certain type of personality at QB and clearly Croft is not it. Many observers at practice felt Croft was a better player. Some mentioned Rhoda's penchant for bad decisions which is starting to rear its head.
I have not seen enough to declare Croft doesn't have "it" as a football player. Rhoda is not performing at a high level, certainly not high enough to win any Big Ten games without a solid defense, which we don't currently have (pending returning players and torn red shirts).