I respect and understand the appeal of LISP. It is a great example of code not having to change all the time. I personally haven't had a compelling reason to use it (post college), but I'm glad I learned it and I wouldn't be averse to taking a job that required it.

While writing "timeless" code is certainly an ideal of mine, it also competes with the ideals of writing useful code that does useful things for my employer or the goals of my hobby project, and I'm not sure "getting actual useful things done" is necessarily LISP's strong suit, although I'm sure I'm ruffling feathers by saying so. I like more modern programming languages for other reasons, but their propensity to make backward-incompatible changes is definitely a point of frustration for me. Languages improving in backward-compatible ways is generally a good thing; your code can still be relatively "timeless" in such an environment. Some languages walk this line better than others.