I like LISP, but I wouldn't say I'm an evangelist. Here's my 2 cents for why LISP has such a following.

1. LISP is easy to start with if you're not a programmer. There is very little syntax to get to grips with, and once you understand "everything is a list" it's super easy to expand out from there.

2. LISP really makes it easy to hack your way to a solution. With the REPL and the transparency of "code is data" model you can just start writing code and eventually get to a solution. You don't need to plan, or think about types, or deal with syntax errors. You just write your code and see it executed right there in the REPL.

For my part, I love LISP when it's just me doing the coding, but once you start adding other peoples custom DSL macros or whatever the heck it becomes unwieldy. Basically, I love my LISP and hate other peoples LISP.