In either case it does not follow that pure functional programming is the answer, especially as it makes "essential side effects" (which are, well, very essential), quite cumbersome. Clojure isn't pure functional, it makes essential side-effects easy, and non-essential (or, rather, dangerous) side effects hard.

I'm not saying that Clojure is the silver bullet, it's just that the article's conclusion does in no way follow from the premise.