First off... he would have failed at the NBA with the Lakers... entirely because of Lebron. Lebron just needs to be player/coach. But college basketball needs to have great coaches. Sure the game is changing... but having great coaches at schools, and them staying at their schools, is good for the sport.
If he would have left for the NBA, I think it would have been the first time in 60 years that the National Championship Football and Basketball head coaches left their team to coach professionally.