This would have created a close-knit group of similar-type schools. Yeah, there were have been a couple that weren't quite pulling their weight, but having 13 teams all localized in the western states would have been a strength. 13 wouldn't be too larger if Stanford or Cal decide to come home*.
In the merger they could have had a "BYU clause" – if a p4 conference comes a calling, we get to leave. OSU and WSU will leave for the B12 the first chance they get. Nobody else is going to invite them.
*We will see within the next 5 years if the B10 and ACC nationwide conferences work out for the schools on either end. My guess is that USC, UCLA, Oregon, UW, Cal and Stanford are going to turn into mediocre to bad teams. UCLA is already poop.