This is a powerful way of looking at things. It explains a lot, even airport security. For example: the optimal number of evildoers to let through airport security is not zero, yet we've gone to extreme lengths to try to make it so. If you sum up the total human lifetimes spent in airport security lines, it almost certainly multiples of the lifetimes lost in attacks.

We often strive for perfection when we're well-past optimal and far into the region of diminishing returns.