[lobster_johnson]

That's one interpretation, but Greenspun never says what happened when he tried to use the correct function; after all, his Scheme program seems to have been complete at one point, which means that rewriting in Lisp was not more "practical" as such.

His point about the Lisp program being smaller is interesting, but still entirely anecdotal: we know nothing about the program, and for all we know, Greenspun was a Scheme novice at the time of the story.

I have a deep dislike for anecdotal "X vs. Y" stories because they don't shed any light on anything; they're just glib, cheap observations that make for a good story (albeit in this case, not that good).