Sure, there are plenty of LDS members that attend and love the U. But, the percentage of LDS students at the University of Utah is lower than the percentage in the state and local community. It has a high concentration of ex-Mormons and a large and vocal LGBTQ community. 

Multiply those numbers and percentages when looking at the fan base. A significant portion of the University of Utah fan base wears red as an emblem of LDS counterculture as much as or even more so than to cheer a sports team.