I tend to think Marcus' lack of fire as a coach is a significant part of the problem, but not the whole problem. I agree that he is "too nice" in the sense that he wants to empower the players; he seems to desire a team-led resurgence; and he continues with that philosophy despite the fact that it has not worked. However, I don't think his teams have absorbed any standard of performance that he sets, and you can question whether he has a standard of performance given what he accepts, and as a result you get the failures that we've witnessed.
Separate and apart from that, I think he has significant coaching weaknesses. He has high rated recruiting classes, but there are key position deficiencies (e.g., DL, WR, punter). And he doesn't seem to understand game day coaching in any material respect. He defers entirely to his coordinators, doesn't interact with the players on the sidelines, and doesn't work the refs. It's made me question whether he's needed on the sidelines at all. I'd also add that his comments about Leonard basically being a game manager before the NIU game were both stupid and naive. That may be true, but you don't need to say it that way.
As an organization, having someone at the helm who is perceived as nice but who is not competent ultimately makes the institution look weak. That strategy may appeal to moms who want to send their kids to a nice place, but in terms of garnering respect in the area in which you compete, it's not going to put points on the board.
Link: Too nice or incapable of molding men?