We can't very well ask them for a 0% failure rate, can we? Mistakes are going to happen, it's the nature of the world. For example, humans try really hard to b

We can't very well ask them for a 0% failure rate, can we? Mistakes are going to happen, it's the nature of the world. For example, humans try really hard to build "failure proof" nuclear reactors, and those still have problems. I claim that's evidence that 0% failure is just not a reasonable goal.