Literally the civil rights movement happened a century after the Civil War. The south is steeped in antebellum attitude. It's impossible to go to any southern city on the east coast without seeing a civil war memorial
People in hyrule were still ALIVE during the calamity, and it's less...
I don't think the world does a good enough job of showing the impact of the calamity. In most parts of hyrule (no seriously like 3/4 at least), it's just a story that geezers tell their ankle biters
I'm not entirely convinced that a "calamity" happened in living memory