I think Detmer has a strong affinity for Bronco and the program. He does have a ranch in south Texas, but he also works a full-time job in Austin. He makes it up to Provo whenever he gets the chance. He has made himself fully available to the program. It's my guess that he plans to enjoy the calm post-NFL life for a while before he's ready to put in the grueling hours of a college coach. He currently gets his coaching fix by helping his father's annual QB camp in San Antonio.
I think that if the administration created the right position for him, he would gladly join the ranks.