It looks like half-serious, half-trolling to me. He (or his troll persona) seems to have written no line of Scheme or Common Lisp ever, and he has obviously no contact to the respective communities.

I can imagine that he has a point with Nu and Cocoa, but I have never worked in that ecosphere, so I cannot judge that.

His comments about REPLs look completely lunatic. Scheme and Lisp practically _invented_ the interactive REPL, and the parenthesis-based syntax makes the implementation of a REPL almost trivial (where does a unit of computation end in Python?). The claim "The s-expressions inherent in Lisp simply won't allow for that." is just bullshit.

So, dear Steven, talk about Clojure, but don't talk so dismissively about things you have no idea of.