[gmfawcett]

There's also a historical componenent in all of this. Modern languages have adopted many features from the old Lisps that were quite unique back then. The same is true with the ML language family: between the two, ML and Lisp seeded a new generation of languages that are, on average, much more powerful than the languages in common use in the 1970s and 80s. (Smalltalk deserves a special mention, but it came later.)

I'm still fond of Lisp, but languages like Python, D, Nim (and increasingly, Rust) offer a lot of the Lisp affordances that I really valued -- in particular, easy compile-time metaprogramming. The biggest missing bits are Lisp's deeply integrated REPL-driven programming, and the use of program images -- which have many drawbacks but also some benefits.

IMO, everyone should write and maintain a medium-sized program in a modern Lisp (SBCL, CCL) at least once, just to get an appreciation for how different the programming / debugging experience is. So many well-integrated tools at your disposal, even at runtime.