In the case of Petrino, Louisville won't get the players to compete with the FSUs and Clemsons of the ACC. He will be an easy negative recruiting target and his coaching won't be good enough to make up for it (at WKU, he got obliterated by a bad UT team that had to hold on for dear life to escape South Alabama; most experts expected WKU to keep it close and some even picked them to beat UT).
As for Pearl, he can no longer get away with hundreds of improper contact violations. He built his career on a foundation of cheating and now he can't do that and dodge the consequences. And he won't have another Chris Lofton to bail him out when half-court offensive possessions break down, as happened much more often than University of Pearl fans want to admit.