BYU hasn't delivered anything spectacular on the field in 20 years. We have had some double digit seasons, but those lead to the Vegas Bowl. The U has a certain cachet with both LDS and non-LDS fans alike because it's just a normal school. BYU's fanbase is almost entirely LDS....and SL County is no longer majority LDS.
I think BYU could regain fans and grow into a program that is popular with the younger generation, but we need a Jimmer type athlete on the football field and a team that rises with him. Bronco is not a darling of the media type coach...so it's going to be players who evoke the kind of enthusiasm that will make fans want to root for BYU.