Actually, BeOS ran on macs. But the point remains, Apple is not in the market position to force out OS competition. They're in a position to make Their consumer device run their OS more easily than an alternate OS. They don't prevent anyone else from launching Android or Windows mobile devices, and they aren't in a position to. Their strongest anti-consumer position is the app store (in the sense that there is a gateway preventing consumer choice), but if you really care you can get around it by jail breaking, or just leave the platform. And if developers cared about their position, they should flood the android market with the apps needed to drive consumers away from iOS.