The guy didn't fail, just recently didn't produce on the field up to what the typical standards were that he set at FSU.
College football is about talent but coaching is a HUGE component of it, as well. When kids leave high school, no matter how talented, they don't know how to play football at the Div-IA level.
Its why you see teams every year like Boise, Utah, Cinci, etc. that don't get the great crops of highly rated high school talent but manage to coach up the talent they have and implement a system that, if they get the players for, can be successful despite what they might lack in talent.