> This "nobody can use Gnome 3 efficiently" is nonsense.
Nobody claimed any such thing.
Consider a simple action of changing a workspace using the GUI/mouse in Gnome 2 and 3, for instance.
Gnome 2 (or Gnome 3 fallback): move mouse to the workspace switcher, click on the workspace in workspace switcher (which you are constantly aware of, just by glancing at it), change of view.
Gnome 3: move the mouse to the activities, wait for hot corner or click, change of view, travel to the right, wait for workspaces to pop up, become aware of the one you want, click on it, change of view again.