It's pretty much a universal concept, and if fans stick with their teams through the bad, it's the exception, not the rule. I can really only think of a couple of teams who truly stick with their fans through bad seasons (Sonics, Knicks... the Lions), and neither Utah nor BYU meet the cut of having a surplus of fairweather fans. I remember the Reid and Crowton days as well as anyone.

I think if BYU ever has a prolonged 3-4 year period of mediocrity (Something they really have not had since before Lavell), you will see as sharp a drop in attendance as most other schools. You just will.