How could you implement macros in any sane way without s-exps? You need an AST and the hoops involved if you didn't have something like lisp would be terrible. Imagine running a macro over python or C code.
(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.