Eh, this reads like damning with faint praise to me. Lots of robust and fast real world systems are in FP languages. Ocaml is estabilished and mature, far from "is it production ready?" category.
Not really meant to be "damning", I'm a pretty big functional programming advocate (I've spoken at the Lambda Days conference four times and the Clojure Conj once).
It feels like the trend right now is to bolt on one or two "functional libraries" into your "normal" language and pretend that that's the same as writing Haskell or Ocaml. People have actually expressed such sentiments to me because Java has the optional type and a "map" function for the Streams API. When I suggest writing something in a functional language, the response is always "it's too hard" or "we won't be able to hire for that", as if engineers are somehow unable to learn new things.
