I really want to use this professionally. Lisp is so much more productive (for me at least) than other languages. I just don't want to have to use much else.

Why Emacs Lisp and not a CL? SBCL actually performs on par with more popular languages for server workloads. Emacs Lisp? Not so much.

I think the article explains this. People are free to write CL versions, personally, I find EmacsLisp the only really practical Lisp.

node.js has been over the performance grounds a lot, it's scalability that matters, not raw per request performance and for that Elnode could score.