BYU was aiming for 6 wins last year and they not only hit the mark, they exceeded it. And BYU did it in style--beating Tenn and USC.
If you're hoping for something better than 6 or 7 wins, you're cheering for the wrong team. BYU Administration and coaches have made it fairly clear that the bar next year (and going forward) is to get to a bowl game (i.e., 6 wins). If they find a few more wins along the way--great. But the program isn't aiming any higher than that, so it's not fair to criticize the program for hitting its goals.
You can wish that they had higher goals, but setting higher goals would be unreasonable unless BYU elected to (1) change its scheduling philosophy, or (2) devote more resources to coaching and recruiting. None of those things are happening, and BYU is content to continue on the current path for as long as it goes. Under those conditions, a composite 58 ranking isn't bad. It's a success.