I long though that perhaps a part of the interview for a tech job should be observing the candidate to put the cart back, instead of, let's say, going through 11 technical rounds of coding in a half-baked web IDE.

Did not put the cart back - that means the same approach will be taken when developing. "It is not my problem. They pay people to do it". Do not hire.

I was returning a cart from the lot to a store and the guy came up to me and said.. please don't do that. If everyone returned the carts that he would get laid off. His full time job was returning carts. He was ex brother in law !