Advanced programming languages

Yes. An understanding of JS is definitely necessary when developing with CoffeeScript. The ambiguity that the parser allows sometimes leads to code generation that isn't at all what you intended. I sometimes find myself going into the JS output to make sure the compiler did what I intended.

Annoying, but at least for me, the benefits of cleanliness and things like list comprehensions and Python-esque list semantics makes it worthwhile.

Then I like how you said 'statephobia'. In case of Erlang they saw the practical difficulty with having one single mutable state across a large distributed system so applied the 'actor-based concurrency model'. Perhaps other, more academic languages, decided to cure their statephobia because of some aesthetic desire, maybe they wanted the functions to look more like math functions, but they both declared war on spreading mutable state, even though they started from different ends of the spectrum.

I agree with the sentiment that often, "once it compiles, it's correct", but people don't stress what Matt Might does enough: "In fact, experienced programmers become adept at encoding correctness constraints directly into the Haskell type system." If you just write Haskell (OCaml, etc.) like you would Python, it's not going to make much difference - it's all about representing higher-level assumptions at the type level, and many people new to H-M languages don't know how to do that effectively.