Colorado currently is awful – as are the other 3 schools you mentioned. But three are the premier state sponsored institutions. The name and logo mean something more than the current product. The three PAC schools have had success in the past (Colorado as a B12 member only).
The location is also important. They are 'close' to other members. I like WSU, but they don't have the name or the location. uu is a superior product, but probably doesn't add additional markets.
Who knows what's going to happen anyway. That's why smarter people than me are making the decisions (maybe). The PAC will probably just stick together and hug it out.