Bronco has failed in hiring effective coordinators.
In my opinion this is the biggest factor that has stopped BYU from getting to the levels that Utah, BSU, TCU, etc. have reached with similar recruiting pools and even less resources.
Bronco is a great recruiter. Great Coach (as evidence by everything he touches or focuses on seems to improve dramatically) and a great leader (the players love him and will do anything for him). He has also represented the church well and used the program to really influence young men into becoming great people.
But he has been foolish in his hiring of coordinators. He has put himself in a position where he has to do everything if it is going to be done well.
D sucks. he takes over and immediately it is better and even becomes dominant. O sucks. he drops D and focuses on the O. O becomes elite but then D sucks again.
Just hire someone that can do a good job so you can focus on what a head coach should be focusing on! Or just take a demotion and only focus on Defense while someone else worries about the head coach stuff like hiring good coordinators and assistants. Its obvious he is a good coach that doesn't have the help he needs. But his inability to pick good assistants has stopped him from becoming a great coach.