He had a great thing going at Michigan and could have settled in there and won for a decade. He had money to play with, he got whatever kids he wanted, the compensation was pretty outstanding and after winning a national championship, he probably had a lifetime contract lined up.
The NBA is a whole different ordeal. I don't think that you have to be a great X's and O's guy and you definitely can't have an overwhelming personality. In college, if players are unhappy, they transfer. In the NBA, if players are unhappy, you're fired and black balled.
All that said, his value will never be higher than it is right now and the good news for him is that if he fails miserably, getting back to a top tier college job, a year after being an analyst on CBS or ESPN.....he won't have to look hard.
Gutsy move and only time will tell if it was the right decision.