Not to mention, there are languages with the same expressiveness as most Lisp-like languages. Dylan and Julia immediately come to mind. Julia in particular makes it easy to convert between code and syntax tree data, so you have arguably the same capabilities as Lisp macros, in a syntax that would appease GP's preferences.

I think another big thing that makes Lisp-like languages (Common Lisp, Clojure, Racket, ...) convenient for this kind of work is the fact that everything is an expression. Having "statements" and "expressions" separate makes writing some programs awkward. I use Clojure at my day job, and the way I write code takes for granted that I can simply bind `foo` to the result of a `case` or an `if` without ad-hoc operators that have completely different syntax from their statement-equivalents.