I can't help but feel, since many of the same arguments against neovim could be said of the rewrite from vi to vim, that this is the natural order of things and the point of open source.
A bit earlier — 1977 at least¹. I guess there was some (actual or alleged) descent from ed (the standard text editor) in the AT&T kerfuffle preventing it from being generally released under a BSD license.
Keith Bostic reimplemented it from scratch as nvi (new vi) for 4BSD.
