BYU's great ten and eleven-win seasons have been replaced with seven and eight win seasons. Even in those ten and eleven-win years, BYU wasn't the best Mid-Major. Each time, Boise State, TCU, Utah, or Hawaii were better.
For the last 15 years, Utah has been consistently good - they have been historically great (undefeated!) twice. They won their BCS bowl games and were the more nationally noteworthy program when the PAC12 came calling. But, if it makes you feel better, go ahead and celebrate BYU's MWC championships (Yay!)
Just remember that most of us would trade every single one of those MWC and WAC championship trophies for inclusion in a P5 conference.