Missed the second reason, which has two parts:
1: There is no guarantee that Windows will boot on an Apple PC86 (without the user hacking the system and thereby voiding their warranty)
2: There is certainly no guarantee that the user will fork over $500 to MS to buy an OS when they already have a perfectly working Apple OS. Yes, some would if they could, but the software developer can't rely on that fact.
Both of which add up to the fact that the developer can't just tell its users to "just boot into Windows" any more than they today can tell their users to "just buy a PC/Mac". If they want the OSX user market, they will have to support OSX.
1: There is no guarantee that Windows will boot on an Apple PC86 (without the user hacking the system and thereby voiding their warranty)
2: There is certainly no guarantee that the user will fork over $500 to MS to buy an OS when they already have a perfectly working Apple OS. Yes, some would if they could, but the software developer can't rely on that fact.
Both of which add up to the fact that the developer can't just tell its users to "just boot into Windows" any more than they today can tell their users to "just buy a PC/Mac". If they want the OSX user market, they will have to support OSX.