As they should. Gruden has become this mythical "home run hire" / savior but in actuality, he's really a 2nd or 3rd tier hire. I'd much rather have Fuente, Frost, or Mullen before Gruden.
Gruden is a great X's and O's coach, but a "Head Coach" in the college game is more like a CEO. College is more about talent development than X's and O's; not that X's and O's don't matter, but it matters less than in the NFL. Gruden's system was already tried at Nebraska under Bill Callahan and it failed miserably. While Gruden is a better coach than Callahan, part of Callahan's problem was always that his offense was too complex for the college game. Gruden would deal with the same issue.
I'm not saying that Gruden couldn't succeed. He's a smart guy and he'd be able to recruit top 10 classes routinely. I'm just saying that there's no real reason to believe that he's a better coach than someone like Scott Frost or Dan Mullen in the college game. As an NFL coach, yes, I'd take Gruden in a heartbeat over those guys, but not as a college coach. And the track record of NFL coaches in college is almost as bad as the track record as college coaches in the NFL. Jim Mora, Bill Callahan, Dave Wannstadt, Mike Sherman, Lovie Smith --- so many more NFL to college failures than success stories. Pete Carroll was the exception.