A lot of schools don't want to deal with BYU because of Sunday play. BYU is in the WCC because they are fine with it. The Big 12 and Pac 12 don't want to move its basketball championship from Selection Sunday to Saturday just for BYU. That would be a serious downgrade in viewership and prestige.

Don't cry about "no good reason" when BYU demands special accommodations for its religious beliefs. Add to that demands for TV rights and BYU becomes more trouble that it's worth.