Growing up as a kid most BYU fans cheered for Utah - they liked seeing Utah do well because they knew the last game of the season BYU was going to crush them by 5 touchdowns.
There was very little hatred flowing from BYU to Utah. It was all one direction.
Then the 21st century happened. And the hate goes both ways.
Boise State fans don’t care about the University of Idaho anymore.
BYU doesn’t care about Pacific, or Pepperdine…we don’t hate those teams despite the occasional loss. But SMC and Gonzaga? Oh most definitely. Those teams are hated.