According to who? I've been to plenty of Sun Devil games, and the feeling I walk away from each and every time is "If only Autzen sat that many people, and had the student section in nearly the first row across the entire stadium..."
I would put a ton of other schools above Sun Devil Stadium "student section being the loudest in the West" before ASU ever saw what the list looked like. If we're talking basketball games, and the cute little charades that are played behind the curtain, then yes, you have a point. But Sun Devil stadium is cleared out by halftime because everyone is either too hot or not interested in the game.
Further, ASU will continue to be the school that does less with more than any other school out there. There's absolutely no reason why that team shouldn't be a power house with the location, admission requirements, scenery (i'm talking the women), and climate.