Because "early adopting" is generally used when talking about beta software, but in this case the software was declared released, but the users' experiences resembled that of early adopters'.
Plus: there are no reports of Ubuntu installs like iPods ;-)
It's also easier to patch software, although it's harder to make it run on hardware someone else designed and who will not tell you anything about how it works. Apple doesn't have this problem either: the least they can do is OSX folks pointing fingers to Macintosh hardware designers.
But I have to admit Apple hardware has the good looks on its side.
