down the strength of schedule, I think it's safe to say the quality of play is a big deal. Yes, BYU consistently shoots themselves in the foot a couple of times each year against teams not named SMC and Gonzaga, but that doesn't make the general quality of those programs BYU's fault. So regardless of arena size/attendance, BYU fans, SMC fans, and Gonzaga fans all have a legitimate grip about the many sub-par programs in the WCC.
So as for the arena sizes, I don't really care. I think it definitely affects the general perception of the WCC, but I think it pales in comparison to the impact of the quality of most of the WCC teams when it comes time to seeding/selection for the NCAA tourney.