"Haskell/OCaml/some other FP meme: it is not possible to write useful programs in these languages"
Haskell: git-annex, Propellor, xmonad, pandoc, shellcheck
Clojure: Riemann, Jepsen, Datomic
Erlang: rabbitmq, SimpleDB, WhatsApp, ejabberd, CouchDB
Plenty of companies built stuff with these languages too. Just saying. Maybe you can't write useful programs in these languages. That's you. Not the language.