I think Bobby was brought back as it was a relatively safe option considering the alternatives at the time (or at least one where the risks could be offset). We needed stability at the helm as we moved into the ACC, not a coach that would blow the doors off for 2-3 years then jump ship again.
Bobby has been exactly that without any of the upside (nor downside to his credit). We are an 8-5 or 9-4 team. That's it....it's all we are ever going to be with BP. 10-3 at our best and a 6-7 at our worst but there's the range, you can write it down. Last year was the golden year, got a Heisman, but that bump bump bump we all felt at the end of last year was the ceiling. He's lost a step on offense, still can't help on the defensive side, maybe a step better on recruiting (arguable considering other factors).