> In particular the common abstractions (Monad, Applicative, Functor) are used very differently in different libraries (everyone seems to want to write her own DSL), so it's hard to get comfortable with third party libraries.

I don’t see how this is true. These common abstraction make reading code incredibly easy most of the time. Many Haskell libraries are based on compositional building blocks. Seeing a monoid, functor or monad instance gets you 90% there in understanding the usage. It’s really the superpower of Haskell that I miss (and badly reimplement) in every other PL.