Why would anyone want to use a programming language that uses product types instead of sum types for the return types of functions which can return errors? Or why would anyone want to use a language that doesn't even let you write a type safe hash table? Also, the fact that Go suffers from the billion-dollar mistake is downright inexcusable. Go is way too error prone for me to sleep comfortably at night, because the lack of a reasonable type system is a constant liability.