That people can make an initial plan that is self-consistent, logical, and foresees and provides for all future use-cases is a basic tenet of waterfall-style de

That people can make an initial plan that is self-consistent, logical, and foresees and provides for all future use-cases is a basic tenet of waterfall-style development. The history of software engineering does not uphold that principle. Why would it be different for language designers?