I don't know if that is true now. Plus, having done my undergraduate work at Utah, I was ready for a change.
But I suppose there were also other reasons. I applied to both schools (I viewed Utah as my "safety" school), but I was immediately accepted at BYU and wait-listed at Utah. That was a little odd, but with the acceptance in hand, I immediately told BYU I was coming and informed Utah to take me off their list.
I also had a feeling that BYU was the school I was supposed to attend at that point. I am a member of the LDS church, so there were religious and spiritual aspects to my decision, but even looking at it from a purely secular standpoint, it felt like a good idea to diversify my education.
Sorry my answer is a little bit rambling. But those were the main aspects of my reasoning at the time. I think mostly it just felt right. I decided to go to law school practically on a whim one day, and although I was late signing up for the LSAT and getting in applications, everything just sort of fell into place.