Apples and Oranges. Didn't Saban come from the NFL? Same for Harbaugh. Big names. Saban has earned his money, Harbaugh makes a lot of noise, hasn't won anything yet.
Mike Riley, a great guy, came from basically zero at Oregon State. They hired him because he was the anti-Bo Pelini. You don't hire Mr. Rogers to light a fire under a dormant program.
Their next coach will come from FCS or be an assistant.