But this introduces additional ast format. Something in between simplicity of the syntax and complexity of the real ast. In lisp like languages you are working with syntactic forms from the language. Seems like extra overhead without any gain.
(And though I came to S-exprs early in my learning, algol-style still is easier for me to parse and read.)
Personally I find Clojure very readable, but of course I don't mean that in some kind of objective sense of the word.