I found Gnome 3 annoying at first but it is just another environment and not particularly better or worse than any other. It is just a matter of using it long enough to become accustomed which is true of any desktop including Xfce. Xfce is similar enough to the styles of the past that it takes little effort for mature users to adapt to it. But is it really easier to use for first time users than Gnome 3 or anything else? What about all these people whose first computer is a tablet or smart phone? These environments are closer to Gnome 3 than Xfce. Which environment will these users find more comfortable.
Consider a recent report which addressed the computer market by combining desktop/laptop computers with mobile devices like tablets and smart phones. Conventional desktop devices have shrunk from 95% of the market to 70% of the market and this trend is continuing. An important metric to follow is what percentage of internet traffic is done on mobile platforms as opposed to desktop platforms. This tells you something about where people are spending their time.
Gnome 3 is an attempt to deal which this paradigm shift that we are in the middle of. The traditional mouse-pointer centered desktop is ill-suited to the touch environments where it greatest growth in computer platforms is today. Gnome 3 can be operated with a mouse but it is designed to be operated by touch once that technology is perfected in the Gnome APIs. I see it as encouraging the maturation of the touch technology for Linux by providing an environment ready to exploit it. I am certain it is not the best solution because it is one of the first. The next ones to come along always learn from the front runners. Gnome 3 will become better and easier to use but it will never be optimal for the traditional desktop since it is intended to be a merger of mobile environment motifs and desktop motifs so its goal will be to find the comfort zone where these two different environments meet.
I found a particular advantage to using Gnome 3 as an engineer which is probably useful at some level for system administrators. I am developing an embedded system that combines multiple computers that I monitor at the same time with VNC. With a simple movement of the mouse, I can shrink the screen to the "window selection" mode which lets me watch all of my computers at the same time. I can select a particular window and zoom in to a particular machine in a moment. I can see a case where an IT administrator may need to monitor interconnected system during setup configuration when it would be useful to watch the interactions of systems in a similar manner. It is more useful than shrinking terminal windows until they fit your desktop.