West coast players have been going east for as long as I can remember. Top players out here either went to Stanford or they headed east - the rest of the Pac had no attraction. The sole reason that the Pac is now (arguably . . . and I love arguing about this!) the best conference in the nation is that more and more west coast players are staying in the West, and a few east coast players are coming our way, and that's mostly about the coaching.
As for fan support: Arizona had little support during the season, but sold out their coliseum for their last WNIT games - hopefully that will translate into more fans next year. ASU seems to have topped out with crowds in the 2000-4000 range. The LA schools will always be friends-and-family-only crowds - it's a big city, WBB hardly rates agate type in the papers. UW cratered after Kelsey Plum left. Utah, WSU, Cal, and Colorado are still languishing. UO will do well as long as they are winning - it's that way for every sport in Eugene. OSU has a more stable fan base - it's a smaller, more intimate town where the fans have more connections to the teams and to each other.
In sum, I think UA has the potential for big crowds if they can get on a winning streak. I think Tucson is a lot like Eugene - a mid-sized college town which is large enough to fill a coliseum but not so intimately connected to the school like Corvallis is to Oregon State. Utah might get crowds someday - their gymnastics team sells out a 14000-seat coliseum almost every meet. But overall, the Pac is what it is.