Recruiting is a zero sum game, especially in a less populated state like Utah. BYU needs every great recruit from the state of Utah possible to complete with the elite teams like Ohio State or Oregon or Georgia or Bama.
The problem is, when the UU is good, some of those recruits go there instead of BYU. Can you imagine BYU’s defense is we had Utah’s D-line. Or our offense is we had Kuithe?
Cheering against Utah has nothing to do with pettiness. It has everything to do with what’s good for BYU, particularly in recruiting.