Edit: We cannot blame people for buildings things that worked when we had a stable climate but are no long suitable for all these extremes. We needed to fix the emissions issue 30-50 year ago to avoid this. We knew it and we collectively ignored it. I get your point, we could've "planned ahead" but if you build something that wasn't suitable / cost effective for the time it was built, you'd be out of business.
50 years ago no one was going to pay extra for a building that might be important in 100 years because we didn't stop burning fossil fuels in time.