[aidenn0]

I can speak for the western 2/3 of the US, but east of the Mississipi, I think the idea of duty went out-of-fasion in the period from ~1965-75. The combination of Vietnam and the civil rights movement obviously led to a distrust of authority, but in also a broader sense a distrust in society as a whole. Social cohesion is supported by duty, but also a requirement for duty; as that fell apart, Duty went with it.

In addition, less cosmopolitan areas were less affected by all of the above, which allowed Duty to persist there longer. That was, ironically, the final nail in the coffin for Duty because Duty became déclassé and the mark of a rube.