Interesting choice of languages. Out of that list, only Haskell is suitable for the argument you're trying to make.
Is that SML or Ocaml? If that's SML, well it's a really poor choice. And what makes you think Clojure is better for functional programming? I'm not arguing that it isn't, it's just interesting seeing it in a list of what are supposed to be better choices for FP. Because in my opinion, Clojure is just as dirty as Scala or maybe even more so. And it's also a Lisp and the styles and patterns used tend to be different in Lisps, than what you do in Haskell or Scala.
That book I linked is not about Scala, but about FP and just happens to use Scala as the language. It's a good book. If you preordered it, it would be a waste to not read it.
Becoming professional, and gaining experience has given insight in helping to choose stack in respect to matureness, stability, tool support, documentation etc. It's not that you cannot write Scala code for production and be happy about it. But I rather not. Writing fast is only one part of it. IntelliJ supports the whole aspect of development cycle, and it's good to hear Scala plugin is catching up. Just my opinion.