It works both way. In military terms, the perfect is the enemy of the good. Often the best move is rapid, violent decisive action now. The term is generally misused in other settings, especially decisions that are made over the course of a year or two.
However, in sports, the good is the enemy of the champion. No matter how much you like a good ole boy Mark Richt-lite coach, no Mark Rick like coach will ever be a champion. No amount of talent will ever overcome poor coaching.
If mediocre is your standard, or just providing a "championship experience/championship embarrassment" for the kids, I guess continue status quo.
My point has never been that any coach that can't win a championship in two years must be fired, as you silly guys try to paint it that way. However, it's easy to know what the soup will taste like just by seeing the ingredients. This guy has basically zero attributes of a champion coach. He literally isn't good at anything, offense, defense, special teams, recruiting, game day x's and o's. Nothing.