It would certainly be really useful to me if I could send a robot to get my groceries and not have to worry about anything. But if, even a small percentage of the time, it leaves with the groceries without paying, or smashes through a window to get in because the store is closed that day, then that's my fault. If the only way to keep those things from happening is that I can't send my robot to get groceries for me, then so be it.
The point is the proposed easy fix is not actually feasible.