Nobody said USU and BYU are on the same level (resources, fanbase and even recruiting).
I'm sure that most USU and UU fans don't like BYU. But, several of my neighbors are USU and BYU fans. And I've noticed less vitriol when I talk with my UU neighbors — because I don't take an obnoxious stance. And yes, I'm a full blown Y fan (flying a Y flag on game days...).