That's not the reason at all.
It's because if you add exactly the right type of specially crafted noise to an image of a stop sign such that, to a human, it looks like a panda--then who is going to be the arbiter that decides "No, it's still actually really an image of a stop sign and not a panda". The machine?
The real reason is the subjective nature of the perception of reality. With the advent of AI, all sorts of schools of philosophy that used to seem like useless navel-gazing are going to find some real important practical applications real soon. This is metaphysics and ontology. On a similar note (not in TFA), in the "friendly AI" debate, we're going to be looking real hard at the foundations of the philosophy of ethics (where does it really come from?), not just the teleological vs deontological (etc) debates we use to reason about law, politics, governance and appeasement of our "justice" instincts.
Or quite possibly we just don't know how to construct the noise yet :P
Deep neural nets should really be called "really complicated composition of differentiable functions" and all the training algorithms should really be called "really complicated function root finding" because that's all these things are at the end of the day, a rats nest of functions with a billion knobs.