Part of the reason is Paul Graham's essay about his experience using Lisp at a startup: http://www.paulgraham.com/avg.html
I personally found out about both reddit and HN by means of deeping further into lisp in the internet, beyond his “ANSI Common Lisp” book which I used in university.
I don’t get to do near as much these days, but the lessons I’ve learned have made me a better developer for sure.
Type safety and pure functions make debugging and refactoring an entirely different beast