The problem with using esoteric languages is multi-fold. First, you have to trust that the original programmers actually know the language enough to not create a massive disaster. Are they comfortable working without a framework, are they knowledgeable about all the issues that arise from building closer to the metal, so to speak? It seems to me that the answer is "no" more often than "yes."
Once this happens, you end up in a read-only code situation, and this is a problem because they leave the project with tons of bugs and downright stupid decisions. You are then left in the position to ask 15 people if they can make dollars or sense of anything written, and if you are fortunate, you will get one "yes." I joke that I know all 50 Clojure programmers in the US, and sadly, that's not much of an overstatement. If you want your code to exist, and you aren't a real somebody, then good luck. If you aren't located in SF, LA, or some other city that attracts talent, definitely do not use Clojure or any other esoteric language!
Of course, I didn't read the article, as it isn't loading at all.