He's a good person, don't think many would disagree with that. But he has a very long career as a head coach and that W-L record speaks for itself.You could do a lot worse than Mike Riley. Regardless of what you think of him he is a good coach.
Probably not the right fit for the Big Ten (too many years on the west coast), but if Riley was still in Lincoln he would certainly have gotten more wins out of the team.
Riley is also a highly respected guy amongst coaching circles. Nebraska lost a lot of credibility for their treatment of him.