I totally see how someone gets sick of it, but I also think someone like Urban eats it up. He's a pretty cutthroat guy himself.
I have heard people say that a lot of current NFL coaches view college head coaching jobs, especially big time college head coaching jobs, as more stressful and perhaps even more difficult than NFL jobs. They don't like the politics, they don't like the grind of recruiting, and don't like the fact that a lot of their success will depend upon their success at convincing a bunch of entitled 17 and 18-year-old divas to attend their school. There is a bunch of stuff besides game planning that they have to think about.
In college you can get burned out recruiting, but in the NFL you get burned out in the film room.