Your question makes a good point. Punishment is only effective at the bottom of the funnel.

A well designed system, whether a computer or an organization should always have controls that guide things to where they should be. That means carrots and sticks.

In a place like a post office, that means separation of duties, audit, and clear lines of accountability. Things fail when nobody asks awkward questions or looks.

I do think that leadership responsible for a debacle like this must be punished. Their incompetence destroyed lives of innocent people.