That.. doesn't make total sense unless these people aren't using their phones either. According to one analytics company iOS 3 has been virtually eliminated.
http://insights.chitika.com/2011/just-in-time-for-ios-5-ios-...
To upgrade you need to plug in your device and sync. Not to mention you generally need to sync to put music on the device.
Something is fishy about this rumor. Are the only people going to the Genius Bar recent purchasers?