In regards to Purescript/Typescript, they're both statically typed and that results in friction when trying to integrate with the existing JavaScript ecosystem/libraries. Erlang/OTP might be different, but there will probably be situations where the type system is either incompatible with a certain library, or the type system is made less strict (e.g. an any type).
That wasn't what I got out of the previous post, it seemed to be saying there was something inherently unsafe about compiling down to a dynamic language.
