The biggest issue with guile-emacs seems to be that the community doesn't seem particularly interested in it.

As a daily almost-everything-in-emacs user, I definitely understand the shortcomings of elisp, but generally speaking it does the job. Yeah guile would be an improvement, but I'm not sure it is worth rocking the boat.

It doesn't seem that the idea that elisp needs replacing has that much currency.

I meant replacing the VM, not the Lisp dialect. The value of Emacs is the elisp code available and the platforms it runs on. I don't think there are many users who like the underlying Lisp implementation's runtime behavior.