Also, if I'm screwing with my .emacs it's nice to have instant feedback beyond eval'ing any changes I make as I go.
That said, though, if I was accustomed to one of my primary tools taking a half-second to start, I think I'd miss it pretty bad if it went away.
Just the fact that people on both sides (glibc and emacs) are treating this so seriously seems to indicate a rather admirable dedication to keeping the quality of the software as high as possible.
A 5 second startup time for a text editor is extremely annoying when all you want to do is, say, type some small commit message.
For remote files there's tramp.
But, I do agree that any sysadmin should know enough basic vi[m] to get around, because vi is almost always available on any unix system. Emacs (or nano) might not be installed.