Over the past 4 years, BYU has had 38.5 million viewers (all data from sportsmediawatch)

UCF has 58.3M viewers
Navy has 49.8M viewers
Utah has 49.6M viewers
Army has 48.1M viewers
Memphis has 45.2M viewers
Cincy has 41.7M viewers
BYU has 38.5M viewers
Boise has 30.3M viewers
Houston has 28.6M viewers

Army/Navy I'm willing to write off as an oddity, given that their numbers come almost exclusively from two games, but UCF, Utah, Memphis, Cincy are clearly ahead of BYU. The gap between Memphis and BYU is about the same as the gap between BYU and Boise.

And if you want to ding Utah for it being mostly about the opponents, then BYU is also being artificially boosted by that same thing (as compared to Memphis, Cincy, Houston, UCF, Boise etc) because BYU plays more high profile opponents.

Don't get me wrong, I'm rooting for BYU, but it doesn't help to bury our head in the sand and ignore reality when it's out there in black and white. There's a lot of BYU "fans" that don't watch the games.