Definitely true in the 80's. Steadily decreasing over time. Less true today than ever. We'll always have them, but significant portion, nope. There have been too many positives in the program; there's just too much to be excited about now to let hate be the main motivator. I doubt many cougs have realized how fun the new conference is after the MWC. Even the bottom dwelling teams are more fun to watch than the middling MWC teams ever were.
Pray you get into a good conference because having every loss mean the end of your season aspirations is far more likely to wear out your fanbase over time than mediocre seasons will for the Utes.