Making radical changes to an incumbent system is difficult and often thankless, even when the new version is, if not objectively better than the previous, very good. Apple encountered this with the transition to OS X. Anyone who remembers the "Classic" environment can attest to how poorly this transition was perceived by many Mac fans. Microsoft has a real problem on its hands trying to convince users that Windows 8 is better than Windows 7.
Ultimately, GNOME 3 feels like a much better designed environment than the previous version. For those that tried an early release and gave up on it, I'd encourage you to go back and try it again.