Or take the example of Google maps. We do not possess a detailed digital map of the world. Yet Google maps does pick destinations consistent with human intent. It does not misunderstand what I mean by "Take me to McDonald's".

Yea. The method for interpreting vagueness correctly, is to try alternative interpretations and pick the one that makes most sense. Sadly, humans seldom do that in an argument, instead opting to maximize some sort of utility function which may be maximum for the interpretation that is easiest to disagree with.