[ufo]

I think the argument for untyped languages is their simplicity. There are lots of things that are trivial to express in a dynamic language but that require extra features on the type system to be able to write on a statically typed language (parametric polymorphism, subtype polymorphism, datatype introspection, and so on). Sure, there are type systems for all of these things but it is hard to have a single type system that does everything at once because things quickly become very complicated and type inference gets harder.