BSU, TCU, and BYU with a bunch of P5 teams. You just can't look at winning percentage in the MWC (or especially the WAC) and say those teams should have more BCS appearances because the SEC/B12/B10/P12 with similar winning percentages have gone to a lot more BCS games. Obviously, the same goes for Utah pre-P12.
Now, I'm not saying that the system is necessarily fair or anything like that, just that this isn't the stat for showing that.