We have a religion that expects obedience to some fairly clear commandments, and they are not negotiable. Drink a beer, give less than 10% tithing, fool around a bit too much-heck fool around at all if you are married-and you won't be able to get a temple recommend or hold at least some church positions. But wear a Yewt tie, write "Not to go to BYU" on your donation slip, and mock BYU fans, you can still be in a bishopric and you get to tell yourself that you are just a bit non-conformist. For some folks, this satisfies an inner need to feel like a bit of a rebel.
On the other hand, my old home teacher actually went to BYU on a football scollie, was hurt in spring ball pretty bad-bad enough that after surgery, it was very uncertain if he would ever play football again, and his position coach asked him to give up his scholarship "for the good of the team". He told them to take a hike, quit BYU and finshed up at the U, and has hated at least the football program ever since. I confess, if that had happened to me, I would not have been very happy either.