No, the point is - flood insurance (on a floodplain) is so expensive people simply don't get it. You can say people should leave if they can't afford it, or they should suck it up and buy it, but it's not going to happen. The USA has the same problem - you couldn't get people to move from New Orleans (until they were actually washed away), San Francisco (an earthquake zone) or Seattle (there's a massive tsunami waiting to go off there any time in the next millennia).
People are stupid. They settle in dangerous areas, then the government will be forced to bail them out. It's not 100% efficient, but the alternatives (letting people suffer, or draconian regulations like compulsory flood insurance or strict zoning laws) aren't politically acceptable. And the costs of the government insuring people just isn't so high that it's completely unacceptable - especially when you consider the economic cost of them not covering people (e.g. homeless people clogging up emergency rooms because they couldn't get their cough looked at when it was simply a mild case of pneumonia).
People shouldn't have to evaluate the risk involved in living anywhere, that is the job of actuators. Their evaluation is presented to consumers through the price system.
If the government didn't bail out homeowners who didn't have insurance, then the risk would be reflected in the price of insurance, and a potential homeowner can then easily compare the utility of living in that location relative to the total cost of owning the home versus any other location. As I said, insurance companies don't even try to offer risky coverage like that because they are competing with bailouts based on compulsory taxation (they are competing with a "free" service). When the government interferes in this case, the consumer is falsely led to believe that the cost of living in that area is lower than it actually is, because they don't have to pay for insurance. Therefore, more people move there than can afford it, and more people need to be bailed out by the government when disaster strikes. It's a vicious cycle.
People are stupid. They settle in dangerous areas, then the government will be forced to bail them out. It's not 100% efficient, but the alternatives (letting people suffer, or draconian regulations like compulsory flood insurance or strict zoning laws) aren't politically acceptable. And the costs of the government insuring people just isn't so high that it's completely unacceptable - especially when you consider the economic cost of them not covering people (e.g. homeless people clogging up emergency rooms because they couldn't get their cough looked at when it was simply a mild case of pneumonia).