DO NOT AGREE
The article is more about how to survive the fragmentation issue.
But fragmentation is NOT GOOD, no matter what.
Having different versions is a natural process. I lived through DOS XX.XX, windows 3.1, 3.11, NT, 95, 98, 2000, XP, 7 and still alive (yes, just because by pass ME and Vista)
But the point is, fragmentation is not good. You have to live with it.