The purpose of war is to destroy, eradicate, and erase your opponent. To say that Apple has won the PC wars implies that the other manufacturers have ceased to be operational, and that's simply not the case. Tides change in business, and a company that was once strong could find itself weak, or vice versa.
Not everyone can afford to pay a premium for a personal computer, nor do they want to. How is their structure any different than that of GM, or Toyota? Is the automobile 'war' over because they don't make as much profit as Mercedes Benz, or BMW?