that he made promises to recruits (and players that were already there) that he can’t keep now. I’m sure he pledged to the administration that he would build up the program. (Despite this year’s success, you don’t turn a program around in one season).
Bronco likes to build up young men who might not have much going for them. And now, after one year, he’s saying “See ya later. Good luck with all that character development and hard work ethic I preached.” I thought he would have been more loyal to his players (and to the university) than that. But, ultimately, we have no way of knowing all the ins and outs that went into his decision to change jobs.