You and I will have a very easy time navigating the world of a command prompt, the average user will not.
There is a reason GUIs won out over terminals, and that is because no one in the main stream wants to touch one.
A good OS should allow you to do every necessary task via a GUI. If there is a Linux DE/WM that can provide an experience like that, I feel like GNU/Linux will have its break through in the consumer market.
I use my "I never need to do something in the terminal" as a basic user acceptance test.