This is a pretty good article and cuts at the heart of the "readability" vs "understandability" debates I see. If we decide reading code is an O(N) problem, where N = number of lines, then his argument makes sense and you might just argue about the constant factor (he states 5, I bet it is closer to 20) between understanding a Java code base and understanding a Clojure code base. But the real issue might be that understanding a Clojure codebase as is O(N log N) or possibly O(N^2) if there are lots of interactions and lots of new syntactical constructs.
Has anyone ever measured a Reading Comprehension score for languages?
Has anyone ever measured a Reading Comprehension score for languages?