'cause they're old (and rich)?
Funny timing. There's actually an article on The Athletic now about this exact thing. Good article for anyone with a subscription.
A conflux of factors — like NIL, the transfer portal and rising salaries — has younger coaches contemplating shorter careers.
To summarize, it's 4 main reasons why the old guard is leaving and why the new guard have no desire to coach as long as the old (into their 70s).
-The great unknown of NIL
-Social media-enhanced tension
-Money (increased salaries for coaches).