Earlier quoted context omitted.
Emacs is not a text editor. Emacs is a portable programming platform and text editing is just the default application implemented on it.
Sounds like overkill to me.
"Any sufficiently complicated C or Fortran program contains an ad-hoc, informally-specified bug-ridden slow implementation of half of Common Lisp."
In the Emacs case, Stallman just made that explicit, implementing Lisp from the start.