The issue isn't that this approach won't be useful in building systems we can interact with linguistically. The problem is in describing the system as having learned a meaning.
It might seem pedantic or like something only philosophers of language would care about. But it gets to the core of how we should talk and think about the nature of AI as NLP gets more and more sophisticated.
Well it may not be very satisfying, but Wittgenstein's point is that there isn't anything more to understand about the meaning of words than the ability to use words effectively. http://existentialcomics.com/comic/268
It might seem pedantic or like something only philosophers of language would care about. But it gets to the core of how we should talk and think about the nature of AI as NLP gets more and more sophisticated.