LISP

It's a slow shit interpreted language, doesn't have libraries, you have only recursion and stack overflow, doesn't have an {b.u.i.o ENTERPRISE-GRADE OBJECT-ORIENTED SYSTEM}, you can do just fact an fibs.
Why do you use it?

I use it because I don't program for a living and that's alright.

I use Lisp because it features things that I need. Namely, data is code paradigm and DSL, and macros.