From my perspective, there seems to be 2 major factors related to animosity of opposing fanbases:

1. Exposure to Church members

The worst fans seem to come from areas of high LDS population who have an ax to grind toward the church. Arizona, Boise State, California schools, Washington, etc.

Meanwhile, it seems fanbases from non-LDS populated areas don't have anywhere near the same venom.


2. Quality of the Program

The 'little brother syndrome' seems to be a very real thing in athletics. Big-time programs by-and-large seem to have big-time fans. Nebraska, Texas, Oklahoma, Notre Dame, Alabama and such programs seem to always treat us with hospitality and respect (even after a loss). In contrast, the fans of lesser programs always seem to have a serious chip on their shoulder.


So it seems the perfect storm is when BYU plays a "small" program in a highly LDS-populated area. UNLV. Utah State. Hawaii. Wyoming. Nevada. Boise State.