Let me preface my comments by saying that I am a member of the LDS church, I grew up as a BYU sports fan, and I have bachelor's and masters degrees from the University of Utah. When BYU talks about exposure, they aren't just talking about exposure for their sports teams. They're talking about exposure for their entire university. You question the thought that joining the Big 12 could hurt BYU's exposure. In a sense you're right. Joining the Big 12 or another big conference would give a lot more exposure to the sports programs, but not necessarily the whole university. I never pay attention to the commercials touting the universities of the schools playing.
When conferences and schools create networks, they're usually trying to score big bucks. BYUtv is primarily about exposure. I've read that contrary to most networks, BYUtv doesn't charge television providers to carry their channel. That aside, providers want other reasons to carry BYUtv. They want to know that their customers will watch it. What better way to get a potential audience than by showing re-runs of football and basketball games? TV providers know BYU has a good national following and so they agree to carry BYUtv. Then on the other hand, BYU gets a nice deal with ESPN so they're able to get some money (maybe not as much as they could get if they were in a big conference) and a lot exposure. If BYU were in the Big 12 and couldn't show re-broadcasts of sporting events on BYUtv, the university could be hurt in the exposure department. Since BYU shows a lot of other things besides sports on BYUtv, you could argue that BYU should join a big conference to at least see how BYUtv is affected, but for now BYU is working on getting BYUtv to everyone, and maybe in the future they will decide to become part of a conference again. But I don't think you can fault them for doing what they think is best for the university.
