This is a really great description of the benefits of this sort of thing. In a code base like Emacs, I could easily see where learning the guts could be very hard / daunting for a new-comer (I've never peeked under the hood for exactly this reason).

You all are scratching an itch, and increasing the general mindshare for Emacs. If Remacs runs out of steam, then the world has some extra people who grok Emacs guts. If Remacs fully succeeds in remaking Emacs, but better, then maybe Remacs just becomes Emacs.