Jim Harbaugh, on paper, isn't overrated at all. If you take into account his success as an NFL head coach as well, he's pretty incredible.
But coaching careers don't just exist on paper, and when you take into account the expectations at Michigan, where Harbaugh was once a star quarterback, and him constantly popping off about this and that, you start to get worn out.
And for approximately $6 million per year, Harbaugh is still 0-5 against Ohio State and 2-10 against teams ranked in the top 10.