There are many excellent non-OO functional languages like Haskell, where functional concepts are mapped to much more elegant syntactic devices, having not much to do with OOP. There, ADTs are not expressed as "case classes", there's no need for implicits and coercions to enable type classes, and one can speak the word "monad" freely and bravely.

However, Scala is not Haskell. Scala's raison d'être is merging FP and OOP, and it excels at it. I'd like to leave it this way.