Nice try, but no. There are things that can be done on an empty workspace, like, I don't know - right click and start something? Go to a place? Create a new document?
Even in your case, where you do have a running application, overview is still a regression, because there are two changes of view and you cannot even see where your application is without entering the overview. (I never claimed things could not be improved in the "classic" paradigm - just that activities overview isn't it).
Please read Windows 8 review by the real usability expert I pointed to a few comments above. It is rather instructive when it comes to Gnome 3. I wasn't even aware of how hard Gnome developers have been looking at Metro before I saw Windows 8 on YouTube.