Emacs's C-x C-c isn't likely any more able to leverage knowledge from other environments than vi's :wq. I guess you could be using a graphical version of emacs and use the menus.
On my system, current versions of vim do appear, by default, to show a screen telling you how to quit. A test of emacs -Q to bring up a default emacs environment in a terminal environment doesn't appear to do that. It instead directs you to the "C-h C-a about emacs page", which isn't likely to help beginners. It probably should at least reference the top-level help at C-h C-h or the tutorial at C-h C-t.
There are text-mode menus in emacs, but I normally use emacs in the terminal with the menus hidden and don't use them. F10 will cause them to drop down, but I'm not sure how intuitive that is. looks further Okay, using emacs -Q to test a vanilla environment, it does look like the menus are visible by default in the terminal. If you're in an environment with mouse support enabled - it looks like gpm in a Linux console works, but curiously-enough, it doesn't seem to work in urxvt, xterm, or gnome-terminal for me -- but at least in some terminal environments, you can use the mouse to operate the terminal-mode menus, so I guess ease-of-use point for emacs there.

EDIT: It does look like there's a GTK-based vim that has graphical menus these days, so vim can probably do the menu thing too, but at least on my system, when I launch it, I get a regular terminal vim instance.