So you mean if OS X won instead of Windows, there would be more competitors, right? Nope, there would be even less, because Apple makes it's own hardware, it would have killed off a lot of hardware companies, AMD, ATI being big examples.
And Apple is going to kill off so many hardware companies because if it wins like Windows, it's going to be the sole arbitrator of who gets to build hardware for it.
All MS wanted was for you to pay the Windows tax. Apple wants to control the hardware as well. Eg. Windows Phone 7 is a OS that various OEMs can run on different devices. iOS is basically just firmware for Apple's devices.