Realistically, the PAC12 isn't going to be taking BYU. We've all accepted that, which is why we focus so much on the Big 12.
And from a geography standpoint, it makes more sense for the Big 12 to expand eastward, and there's no shortage of good options that way (UCF, Cincy, Memphis, Houston). If we want to be the preferred option over those teams, I think the best way to do it is to show out on the field and be the top member of that conference.