Also: Emacs is rarely if ever used in the terminal today, and exiting it through the standard desktop protocol ([X], Ctrl-[Shift]-Q, Alt+F4, ...) always works.
I use emacs in a terminal all the time (usually in a tmux session, actually). That's how I learned it (in pre-GUI days) and so it feels pretty natural. I never use the mouse with emacs, even in a GUI session.
Note that GUI emacs doesn't mean using a mouse. I use GUI emacs but almost never interact with it with a mouse, I just have a server-enabled emacs running fullscreen in one of my virtual desktops.
We get so many people using it in terminals in #emacs. Obviously there's no way to know how many people are not using it in a terminal because they won't be asking GUI-specific questions. I and a few others do try to discourage the terminal users and nudge them towards the GUI which is more featureful, but some people really want to use a terminal at all costs.
I don't think that's true. System administrators will happily use it in a terminal. I'd often deliberately run emacs -nw when something requires a quick edit and the GUI would be imposing.
