I'm gonna be a cynic and say this is money following money and Yann LeCun is an excellent salesman.
I 100% guarantee that he will not be holding the bag when this fails. Society will be protecting him.
On that proviso I have zero respect for this guy.
Um, why would anyone be "holding the bag" and who needs protecting by society? He's not taking out a loan, he's getting capital investment in a startup. People are gambling that he will do well and make money for them. If they gamble wrong, that's on them. Society won't be doing anything either way because investors in startups that fail don't get anything.