Because Clojure ignores Lisp. Put that gun down, and let me explain. Lisp is a process. Progress is measured in decades. Lisp gets lexical scope right, for example, simply because we have a head start of decades over the competition others. I'm quite certain that the unwashed masses will discover macros around 2020 and hygiene around 2040. It's simply a matter of time. Lisp moves slooooooooooooooo