3 Reasons
1. The pac 12 is much (MUCH) better now that it was in the BCS buster era (06-10) when TCU, Utah, and Boise were busting the BCS. I argue that it is at its zenith. The Pac 12 is so much better now that it was during that era it is not even funny.

2. Whittingham actually struggled in his MWC years if you approach the data with the assumption that 08 was an anomaly year.
Outside of 08, Whittinghams MWC teams averaged 4 losses a year and 3rd place in the Mountain West.

3. Utah has struggled without a consistent, healthy QB. This is Whittingham's 10th year. As far as I can tell he has had a consistent, healthy QB in only three years->07, 08, and 10. (Please correct me if I'm wrong). In those three years (all, coincidentally MWC years) Utah had 4 losses, 0 losses, and 3 losses respectively. Here are how may losses he had in the other years (with a lot of qb issues some years worse than others) 5, 5, and 3 in his MWC days; 5, 7, 7 in his Pac 12 days. Again coincidentally the two 7 loss years occurred during the absolute two best years the Pac Conference has ever enjoyed. Edit: Note on the 3 loss year that was when Cain was playing fine and they decided to go with Wynn not because of injury but because Wynn was better so it can probably be argued that 09 didn't really have qb issues.

For the record BYU would be struggling too in the Pac as well if BYU was playing the Riley Nelson/Heaps combo. However, if we have Beck, Hall, or Taysom this year, we would be competing just fine.