While I generally agree with your point, it seems to me like that specific scenario could be solved with a dead man's switch contract. Not ideal, but still better than other cases.

I got the impression that the answer you'd get from the Ethereum team is: at the worst case, this is just as bad/good as the current system - i.e. real world effects have to be mediated by an executing authority, same as a real world contract. They would add (and I agree) that smart contracts still have advantages, even in this case.