There are Ute fans who indeed hate BYU and BYU fans who hate Utes.  I know many Ute fans who do not hate BYU and BYU fans who do not hate BYU.

There are obnoxious fans on both sides.  It is best to ignore these people.  Hatred like this is what hurts society IMO.  The same thing happens in politics and it is nonsense.  There is no one person I agree with on everything, but I do not hate them because they cheer for a different team or vote for a different party.

Making an absolute statement that Utah fans hate BYU is not fair and simply wrong.