I believe that BYU had nine lose-able games this year.
I would argue that if BYU had Boise State's schedule, there would may be 4-5 lose-able games (FSU, USU, Boise, Wyoming, Air Force).
It's must easier to rack up 10+ win seasons against MWC level competition.
BYU may end up beating 4 of the top teams in the MWC this year and still end up unranked and forgotten. If tthey were in the MWC and had some luck, they may have won the MWC and would be competing for an NY6 game (similar to Boise right now).