A very good discussion and hard to disagree with conclusions. Also, educational.
I am a bit sad that Roc is following similar pitfalls as Elm in its quest to be simple by rejecting to have more advanced type system features. That just does not work. In dynamic languages you can opt for minimalism because everything goes by default but in fully statically typed languages things can painful quickly. Even golang had to add generics.
Still many amazing ideas in the language. The platform concept is pretty neat. Not doing implicit currying is a good move.
One thing that makes Go's restrictive type system more bearable is a fantastic stlib package for analyzing and generating Go code. I wonder if Roc will get anything similar.