The "Google Experience" has always been an optional part of Android that required additional licensing, but all the major Android manufacturers have licensed it. The lack of it means that this diverges from the typical Android device much more than Samsung, HTC, or Motorola devices. When you throw in the fact that the main shell is considerably different (a content browser rather than a widget environment), I'd say that the use of the term "fork" is understandable, even if not quite right.