If you look at what happened with Mark Pope, it's actually got a lot of parallels with what happened with Bronco when he left.
Both talked a big game, but ultimately didn't deliver in the biggest moments.
Both guys wore thin on the admin and on the fanbase.
Both went on to higher-paying, "bigger," "better" jobs, with "our blessing."
Both were followed by hires that were enthusiastically embraced by the fans.
I'm sure this is the case everywhere, but it's especially true at BYU: when you make it about yourself and alienate your allies (AD), your days become numbered. Mark Pope did not have a stellar HR file at BYU, and it was well known that he wasn't totally in the mold of the brand. His days were numbered as soon as he stopped notching wins.