I'd sure like for us to try that model again, although technically Mac fits that bill! Seriously, I know what you are saying. Why can't we get a proven and experienced HC that has been successful against the elite in college football instead of these guys lately that come in with training wheels? Don't know for certain, but I think that there may not be that many of them that fit the criteria and those that do are comfortable (as much as anyone depending on the late teens and twenty-somethings for their livelihoods can be) and very well paid. Why move if you are reasonably happy and you don't have to? If they happen to get canned, most are likely sitting on a big pile of cash, so there might not be much incentive to jump back into the arena
The best coaches nowadays don't seem to be the vagabonds of past days. They're maybe more like corporate executives with huge stock options.