Oklahoma's .353 is sort of a special case.
Gary Gibbs succeeded Barry Switzer. He had played for Switzer and was a coach for him at OU. He righted the ship, which Switzer left under probation. And he had a decent record (44-23-2, .652), but he was fired because he went 2-15-1 against Texas, Nebraska, and Colorado. Then Howard Schellenberger was hired, and fired after one year (5-5-1, .500). At that point, OU hired John Blake, who had played at OU under Barry Switzer, was then coaching for Switzer at Dallas, and was hired on Switzer's recommendation. (I believe he was dismissed from Dallas right before getting hired at OU. He had complained to Switzer that Troy Aikman was a racist who treated his black teammates differently than he did his white teammates. The black players all supported Aikman against Blake.) The idea was that he was a great recruiter, and if he would hire a good OC and DC, he could let them make the major decisions. Then when it was immediately apparent that he was going to fail despite the good coordinators' work, firing him got tied up with the racial angle. So he got three years to prove himself incompetent (12-22, .353). On the way out the door, he instigated racial unrest within the program that caused several black players to quit, and he destroyed all the recruiting files so that Bob Stoops would have to start from scratch.
He then went on to be a dirty recruiter, as I'm sure he was at OU, for Mississippi State, Nebraska and North Carolina. He helped get North Carolina on probation for recruiting violations, costing Butch Davis (his H.S. coach and science teacher at Sand Springs, OK) his job with the Tarheels in the process.
I'm sure there are comparable examples at other schools. Sometimes programs just put up with a failing coach, or give him more time to fail, because of extenuating circumstances.