College basketball programs are only as good as their coach. Two wonderful examples are Indiana and UCLA, programs that belong in any conversation of blue blood programs, but that have had varying degrees of success since their legendary coaches left. UNC and Kentucky had some shaky years where they were able to right the ship with quick firings and the right hires. We have no idea what will happen with Duke and Michigan State when their legendary head coaches step aside.
And when they do step aside, where is the incentive for an established head coach to leave? Look at what occurred with Ben Howland when he was at UCLA; the three straight Final Fours quickly faded from memory when the Bruins struggled a bit, and he was forced out. Why would the likes of Gregg Marshall, Mark Few, Chris Beard, not the mention the likes of Tony Bennett and Jay Wright leap at these jobs? Especially in a case such as Michigan's, where you are replacing a very successful coach who's set the bar so high?
While this isn't of Michigan's doing, I wouldn't be surprised to see it go the way of head coach searches at places like UCLA, NC State, Illinois and other purportedly great jobs in recent years where candidates weren't exactly rushing forward. Why risk a good or great thing at Gonzaga, Wichita St, or Texas Tech when the money and acclaim and access to the tournament is as good, if not better, than the risk involved with moving on to a job where you're replacing a really solid coach, if not a legend.