KDE4 was released when KDE3 was still seeing support. Gnome 3 dropped Gnome 2 entirely, and they even dropped the "compatibility mode" old desktop around the 3.

KDE4 was released when KDE3 was still seeing support. Gnome 3 dropped Gnome 2 entirely, and they even dropped the "compatibility mode" old desktop around the 3.4 release I think, well before most people were keen on switching to Gnome 3. The early adopters of both complained about how different everything was, but at least in KDE land version 3 was still available for a while. It took the Mate project to maintain Gnome 2.