It's also just really weird, when you step back and take a good long look at it, to see people getting worked up about hacky ways of doing things within the context of a language that implemented sum types the way Scala implemented sum types, and that implemented typeclasses the way that Scala implemented typeclasses.

Which, I don't want to be too down on Scala. Overall, I like the language. Scala's real weak point is its culture. There's a decent risk of cognitive dissonance when you try to wrap an ethos of design purity around a language that's always been a bit of a communal experimentation project.