I have had this thought. Jokes about needing a good editor aside, I wondered about making a unikernal that bootstraps enough to start emacs.
The issue I see with the idea of lisp-all-the-way-down is that most people don’t want to write filesystems and device drivers. I know I don’t. I mean I find them fascinating, but I usually have a specific app I want to write. I don’t want to write device drivers on my way there.