[the1024]

(author here)

borplk hit this right on the head - the public/private distinction not sufficiently nuanced enough to handle the requirements of more complex codebases.

To put your example in other words, I simply want baz scoped to foo. baz may be public for all members and sub-modules of foo, but external uses of baz outside of foo would create brittle and unwanted dependencies across my codebase.