tl;dr

Currying is nice when whitespace is function application and ugly and inconvenient when you have to write foo(x)(y) and the libraries you deal with aren't consistent about this. Currying in Haskell is nice for exactly these reasons.

Also, https://www.amazon.de/Das-Curry-Buch-Funktional-programmiere...

For the German speakers amongst you, a friend of mine also just submitted her book about functional Javascript for review at O'Reilly: http://www.amazon.de/Das-Curry-Buch-Funktional-programmieren...