He pushed too hard and made far too many ridiculous requests (along with others in the AD and admin) that caused the invite of TCU. They were so concerned that the Big12 would fall apart and that BYU would have to work on going independent again. From one source in the AD I talked to, Holmoe had absolutely no interest in the Big 12 during the 2011 debacle. Look how far the program is fallen in such a short amount of time.
If I could make three changes at BYU right now, it would be to replace Richardson, Holmoe and Santiago in that order. Again, as I have said before, Tom is a nice guy, but is in over his head. Val Hale is a nice guy too, but was not skilled as an AD either.