See above post.
Second, I would gladly play for a MWC/AAC conference championship than know what we already know now, the season is over. We won a NC by WINNING WAC trophies for years and years. Why is that? Because we built a reputation and culture of WINNING.
What is the culture and reputation of BYU now? What has it been since Indy? Definitely not a "winning" one, certainly not one of being consistently ranked.
If P5 is the ultimate goal, and I believe it is for everyone. Then we need to be in a situation that makes our football program in the most attractive position. Indy hasn't made our brand very attractive, we don't win and have nothing to play for. By going to a G5 conference, we should be able to get back to the winning ways of 10+ games a season and being much more consistently ranked. (Dream scenario) If we could do this and get to a NY6 bowl or two, how much more attractive would our program and product be for P5 inclusion when the time comes?
Dominance in a G5 league has lead to 2 school being moved up to P5, floundering in the mediocrity of Indy is not a proven path.