Suggest that you compare GNOME 2.0 with GNOME 2.32. It changed hugely over the years. GNOME 2.x was released over a period of 8 years or so. It has been a bit over 2 years already since GNOME 3.0 was released.
Historically, GNOME has provided a very consistent desktop. Where is the data showing that a fork is viable? We do have data on various abandoned forks. I have not seen a fork going around for 8 years straight :P