This completely ignores incentives. If insurance isn't allowed to charge people more who live in fireprone or floodprone areas, more people will live in such areas, and overall society will have to spend more money rebuilding when disasters inevitably hit those areas. Personalised insurance pricing would allow insurers to charge much more to people living in such areas, which incentivises people not to live there. It's also a moral issue: if everyone pays the same rate, then people who did the right thing and chose to live in an area that wasn't fire or flood prone are subsidising people who did the risky thing.