The reason why college coaches almost never translate to the NFL - Harbaugh is considered a "good" one and he only had 3 quality seasons in the NFL - is obvious. In college, they have as much or more talent than the other teams they play. Then they win using that better talent, are considered "good" and go to the NFL.
In the NFL, they have as much or less talent than the other team. There's only so much coaching genius you can do when the other team is better than you everywhere.
Meyer is a particularly egregious example of this. His teams at Ohio State were unbelievably stacked: Carlos Hyde, Zeke Elliott, JK Dobbins, Michael Thomas, Terry McLaurin, Curtis Samuel, Parris Campbell, about 5 OL that are starting in the NFL, both Bosa brothers, Ryan Shazier, Darron Lee, Marshawn Lattimore, Gareon Conley, Denzel Ward, Jeff Okudah, Malik Hooker. On defense alone that's 9 first round picks, which is 9 times as many first round picks as the Jaguars are going to have every year.
I'm not saying that Meyer isn't a great coach, he obviously is. But it's a matter of fact that he's played with way more talent than the competition for the last 15 years. Not to mention he's now quit twice. He's not someone I would put my faith in to turn around an NFL franchise.