"why hang on to a dead word?" Because it doesn't refer to a key. It's more of a identifier. It would be considerably more confusing to substitute whatever key

"why hang on to a dead word?" Because it doesn't refer to a key. It's more of a identifier. It would be considerably more confusing to substitute whatever key you think it should be. Cmd? Alt? Opt? Esc? When I see "M-" in the literature, I know what that means and translate it to the relevant keystrokes. For instance, M-x for me is actually "C-[ x". I've customized it that way. However, we have a lingua franca for communicating commands despite the personalizations.