see and the "real" Bronco are two different people. Bill Riley on ESPN 700 claims that he thinks Bronco will bolt in a year or two. They all claim the DC Bronco (pre-head coach) was much different than this Bronco. They have all mentioned that the church has put a lot of this on Bronco and told him that this is what you will do as HC of the Cougars.
I don't know if I buy it completely, but the point is, BYU may be the most difficult school in the country to coach at (restriction wise). You can only recruit from a very, very limited pool (one that is getting more limited with how much Kyle is focusing on in state LDS kids). You are expected to be as successful as a top-tier BCS school. The HC is a very hard thing for anyone to live, especially 19-25 year old kids who are completely over-hyped down in Provo and are told they are the end all be all.
The point is, BYU will have a very, very hard time finding a top-tier LDS HC that will be willing to come to Provo and take on all of that. Then throw in that BYU requires their coach to do firesides, be a psuedo-GA, etc, etc...well, it's is tough job. There is a great chance that there isn't another coach out there that can do all of that and win 10 games a year, every year.