There's a weird culture in Utah, but it's less prevalent at BYU and even negligible if you have the right roommates. The majority of BYU students are not from Utah.
You can live with diverse people from various areas. I had great roommates from Chicago, San Jose, Montana, Houston, Missouri, Oregon, Oklahoma, Los Angeles, New Jersey, etc. We did not have the weird Utah culture. It was a great environment.
About half the time I had no roommates from Utah/Idaho and the other half just one. And they did their own thing.
The 2 weirdest roommates I had (from Utah) were NOT BYU students. But they were a minority in the apartment and neither lasted with us more than one semester.