Ledee didn't like the way he was used. Holtmann recruited him to be a 4, but because of Potter's departure 2 days prior to the start of the season, Ledee had to fill the role of a 5. I chalk up Ledee's unhappiness as being an unfortunate circumstance (the backup 5 leaving just prior to the season beginning).
When Gaffney committed, he talked about his goal to become a player like Keita Bates Diop. But KBD didn't become the B1G POY until his 4th year in the program. You have to think that Holtmann would have thought that Gaffney would have the patience to develop into a KBD-like player by his 3rd year in the program.