That doesn't seem to be a problem for users of those libraries: there's an hidden assumptions in the post, that every person on this planet approaching Java has

That doesn't seem to be a problem for users of those libraries: there's an hidden assumptions in the post, that every person on this planet approaching Java has to take part in its use cases. Especially FP enthusiasts and hobby projects developers. If it's engineered to where it is, some call it "over", others call it "just righty"