He was not, macro libraries like defmacro and define-syntax were later addition to lisp. Well before formal macro systems were implemented, code-as-data was par

He was not, macro libraries like defmacro and define-syntax were later addition to lisp. Well before formal macro systems were implemented, code-as-data was particularly useful for implementing the eval function in Lisp (the Lisp 1.5 implementation takes up less than a page), which greatly simplified the process of implementing compilers and interpreters.