The social arrangements that produce responsibility are arrangements that create coercion, of some sort.
You can never do merely one thing. The law applies to any action that changes something in a complex system. The point is that an action taken to alleviate a problem will trigger several effects, some of which may offset or even negate the one intended.
(Technology reliability) x (Human reliability) = (System reliability)
The optimum population is, then, less than the maximum.
Every plausible policy must be followed by the question 'And then what?'
It is a mistake to think that we can control the breeding of mankind in the long run by an appeal to conscience.