This is not multi-million dollar college football here. $150k is real good money (I'd love to make it!) but at that level there are other important factors for a family. And Mel is making a decision for his family--they have lived in Ann Arbor for decades. They have a home they like. They have a large network of friends, familiar places to go, things they enjoy. It's hard to uproot all that to go to an out-of-the-way place for a tough job that pays decently but not so much that you will be set for life. Who knows if he will still have that job in five years? If things go sour, that means they move again--and it might be hard to get a job as good as the one he left. Even if he never gets the Michigan head position, he has a pretty good job now.
MTU has a great history, but a dreadful present; it will take extra work to get the right person in place. Probably some luck. I hope they do, but it's not a slam dunk.