"it's just pointless overhead to make the programmer worry about that"

You are incorrect, removing this distinction actually adds overhead of keeping a type in mind when reading and working with code. And overall selector operator in Go is pretty bad, no need to defend it, it forces you to always keep in mind some things, like not to collide with a namespace, because there is no :: operator for namespaces and always look around where the thing is defined, because it's not obvious whether it's a namespace, an interface, a struct or a pointer receiver.