Commercially successful end-user Unices (Android and OS X/iOS) have not proceeded as Unity and Gnome3 are, by trying to reduce the existing complexity from above. Instead, they have burned most of it to the ground and started over.
Trying to simplify the existing system by brute force is really not a strategy that is bound to work well. You'll probably never get things simple enough, you'll break things along the way, not to mention cheesing off existing users.
Then again, burning everything to the ground has its own problems (see Netscape 4) especially if your team is geographically scattered, mostly part-time or volunteer.
I really do not know what the right answer is, but I think the question I have in mind when I use Linux is very different from the question that Ubuntu and Gnome are asking. Mostly I'm happy that my new Debian stable installation still comes with Gnome 2 out of the box.
The printer configuration is a prime example of this - they have simplified it, and broken it horribly. It does not work in 99% of cases where the printer is not directly connected to the computer. You may argue that this is an edge case and that most printers are directly connected, but I think you would be surprised by how many printers are networked today. My parents have a wireless printer, it is not directly connected to anything, and it is impossible to set up using Gnome 3 control centre because the name has a space in it. Want to change the name so you can install the printer? Tough. You cannot do it unless you install the much older "system-config-printer" package.
Other things, such as being unable to set your desktop wallpaper to something outside of the root Pictures folder (It is not recursive, so a photo in ~/Pictures/Holiday-Shots/ cannot be set as your wallpaper), are what upsets me about Gnome - it could be fantastic if so much work was not going into removing features at the sake of making the UI a little simpler.