I guess I don't get the apprehension about Gruden as a coach? Sure he took over a great situation in Tampa and won a SB with Dungy's players and Kiffin's defense, but does anyone remember the team they played in the SB that year? Those were Gruden's players that Bill Callahan took to the SB, that was Gruden's offense that was #1 in the NFL, and Rich Gannon had a career resurrection once Gruden got a hold of him. The Raiders were a mess before he got there and have been a mess since he left. If you're going to knock him for winning with someone else's players, give him credit for someone else winning with his players. I also think that the blame for his lack of success in Tampa has as much to do with the owners as it does Gruden. They never gave him the players (specifically a QB) that he needed to succeed. On top of his success in Oakland, he has worked with and for some of the finest minds in football history including Bill Walsh, Paul Hackett, Mike Holmgren, Andy Reid, Monte Kiffin, Ray Rhodes, etc. in addition to the recent studying he's done with Chip Kelly concerning his unique Read Option Spread Offense. I'm not trying to say he's god's gift to football, but you can't dismiss his resume.
Even if you think he's just an average NFL coach, it's common for average NFL coaches to be very good in college. Pete Carroll, Nick Saban, Butch Davis to name a few...Barry Switzer, Steve Spurrier, Bobby Petrino also. Success in the NFL, or more accurately lack of success in the NFL, doesn't translate to college football the same way.
And if you think the initial recruiting draw is all Gruden could pull in before being a let down, then I think you're way off base. Say he hauls in a top 5 recruiting class this offseason (just hypothetically, not saying he could or will do that), he's got some great players on the roster right off the bat to add to the assortment of talented players already on the roster. You have a big collection of uber talented players, you're going to win some games especially if they feed of the confidence that Gruden exudes. So if you have a successful season right off the bat, that will breed excitement not only for fans but also recruits. The initial excitement of Gruden will continue and he will haul in another great class. That's a hypothetical, but that's exactly what Nick Saban has done.