My understanding is that Emacs is not really Unix in flavor or mentality. GNU's not Unix, remember. :-)
To the best of my knowledge - i.e., I've read somewhere - Emacs is a derivative in style from Lisp Machines at the MIT Lab. It's not really a Unix program.
Unix is an aesthetic. It's squishy. Emacs is a text editor. Editing text is very much a Unix Thing. Emacs does a lot of other crap too, most of it (email, terminal emulation, IRC...) intended to replace or augment some other core Unix Thing. Is putting all those Unix Things into a single box (that isn't unix) a Unix Thing? Probably not, but most of us forgive emacs that transgression. Don't use the crap that doesn't fit your world view, and it remains a unix tool.
Emacs predates the Lisp machines, btw. The original was written (as TECO macros) on ITS. The Lisp machines came out of the same culture and thus had their own emacsen. But GNU Emacs that we are all using today was written on Unix from day one.
However, Emacs still holds on to all the unique ITS key combos, which is why I always hit ^W and wonder why that word didn't get deleted.
There's a public access ITS system over in Sweden, or you can grab an emulator and run it yourself. I recommend trying it just so you can see how Emacs and Info have remained essentially the same (RMS's sad devotion to that ancient religion, etc)
To the best of my knowledge - i.e., I've read somewhere - Emacs is a derivative in style from Lisp Machines at the MIT Lab. It's not really a Unix program.