Just pointed out what's wrong with MOS.
Well... take out the word Mac from what you said and replace it with, say, computer, and you can say exactly the same about AmigaOS4 too. As in:
AmigaOS4 runs on limited variety of computers that are extremely hard to find today. The computers that AmigaOS4 can run on today are slow and obsolete by current computing standards as well.
So what's the point of your post, really?