I agree with you, those who are in flood prone areas and ‘know’ it should pay for the full cost of their flood insurance.
But on the other hand what about those floods that have been caused by the Corps of Engineers, The Mississippi River Levees that were broken in Missouri for Example. Or the Floods in Fargo, As I understand it the Corps was told there was a danger from excess snow pack and rains in the Fall and Winter. They were told they needed to reduce the pressure on the dams and flood control system before the spring thaw.
So other than Mother Nature the Federal Government is a major player in the cause of floods or the exacerbation of the floods.
They are still living next to a river! What do they expect? If you live in an area that has a history of flooding. You assume the risk.
It is the height of hubris to assume that man can control mother nature. And anyone who takes that belief will suffer from it.