> people are not very careful when they buy a chocolate bar
Ok..sure, but I think it's sort of pedantic to bring up a class of contract that, obviously, nobody in this thread is talking about. It's a bad example anyway; even if you are being pretty careful it's simply not a risky transaction and therefor out of scope for complicated enforcement mechanisms like smart contracts.
I don't think smart contracts are very well suited to unsecured lending, at least not with available software. There would be no incentive to pay it back without some mechanism to force collections. Collateralized loans, however, is a great use case that exists already.
This is early stage tech, the scope is pretty small. I don't think anybody is arguing the contrary.