On PC you have windows dominating the market
I'm not sure this has any relevance at all - should Apple have adopted the same logic?
Post Commodore, Amigas did not embrace PPC to "take on Apple". Apple made a decision to move to a platform that performs better all-round (x86/x64), not to "take on Windows" (if they had made the decision for that reason, it would be regarded as a failure as their desktop/laptop market share is still something like <10%).
As I understand it (but I can't find a corroborating source for this), the only reason that Apple didn't make that decision sooner was that Steve Jobs fell out with Intel because they wouldn't give him the good deal he was looking for.
If Commodore had survived and made the move to PPC (or whichever hardware platform), the majority of the community would have gone along with it as long as the OS was basically still there. Those who didn't want to go along with it would have found another platform (or perhaps there would have been an effort to create something 'Amiga-like' while trying to avoid the wrath of Commodore). Considering I still have a soft spot for my Amiga-using roots, I'm pretty sure that if Commodore was still around today and had produced something with an Amiga-ish that wasn't a complete joke, it would very likely be sitting alongside my PC right now.
