The NFL is the ultimate copy cat league, and because Jim Harbaugh went from Stanford to have stunning immediate success with the 49ers, and Greg Schiano left Rutgers and presented a solid base, if not a very good record (9-7) at Tampa Bay, all of a sudden you see NFL teams looking at college coaches to fill head coaching vacancies.
Part of this is a dearth of quality of NFL assistant coaches ready to move up the ranks, but come on, isn't this getting desperate?

Brian Kelly as an NFL head coach would be a stretch

Oregon's Chip Kelly, for example, runs a mad scramble offense that isn't remotely like anything present or past would or actually work in the NFL. He has nothing resembling the NFL on his resume and his big stop before Oregon, where there was a very solid base when he moved there, was New Hampshire.
Notre Dame's Brian Kelly, interviewed by the Philadelphia Eagles, worked his way up the ranks from Division II Grand Valley State. He, too, has no NFL pedigree.
I understood the idea of Penn State's Bill O'Brien as a head coach because of his NFL ties. Ditto for Syracuse's Doug Marrone, who was named head coach of the Bills. But head coaches with no NFL background at all?
Harbaugh was a very good NFL QB. Schiano spent three years in the late 1990s as a defensive assistant with the Bears.
Also, look at the busts among NFL coaches from the college ranks down through the years: Nick Saban, Steve Spurrier, Mike Riley, Bobby Petrino. The list, honestly, is endless.
And please, don't bring up Seattle's Pete Carroll. He was a head coach in the NFL, and a longtime NFL assistant, before he became a college head head coach at USC