A big portion are (including many of the Apostles, some of the First Presidency and many in the Quorum of the Seventy), but the University as an institution and a large portion of it's faculty are openly hostile towards LDS and the church and towards BYU, though BYU is the superior/higher ranked institution.
I see what you are saying and I get the frustration and why they would feel the way they do. But they take things too far re: harassing, pouring drinks on us, spitting on us, cussing at us and children at the games, openly mocking our religion. One guy took a sacrament tray from a local church and repurposed a sacrament trey for jello shots. A friend had her uncle punched in the stomach while at a game in Rice Eccles when we played them a few years back and someone else had their car vandalized. They take it way beyond rivalry banter into pure hostility and the LDS Ute fans turn a blind eye to it and don't speak up about it. I remember the reports of Ohio State fans from when Texas played them in Columbus in 2005, it was like that but worse as the hostility follows us into their stadium.