LeCun is right. Take a robot and put an untrained neural net in its brain, then send it out into the world and wait to see what it learned. Do you think it will learn anything? It won't- because it will observe most events a single time. And neural nets don't learn that way. They must be trained, painstakingly, at great length, cost and effort, only "in the lab", on vast amounts of data and compute. And once they're trained, they're trained. They cannot learn anymore. They cannot change their model. Unless they are retrained. From scratch. Painstakingly, at great cost, on vast amounts of data and compute. Again. And again. And again.
Contrast that with the intelligence of -oh, I don't know, a squirrel? A squirrel is born with a tiny brain, smaller than the nuts it will subsist on throughout its life. When it's born, it has never seen a person, never seen a crow, never seen a cat. When it dies, it has often not only seen, but learned how to survive all of that.
A squirrel. Even a cockroach can learn more than it is born with. The smartest neural nets today are no smarter than a simple beetle.
I have no idea how Hinton has managed to convince himself that a machine that is incapable of learning once trained will take over the world. A machine that is less capable intellectually than a roach, or a squirrel. That just makes no sense.