Florida's not a state where I have experience, but I have considerable in the insurance industry. Only if the risks are similar in nature does that work out.
To give a good example, the risk associated with a driver who is still driving with 4 drunken driving tickets is incalculably higher than a driver that has "normal" driving habits. There aren't enought of the 4 drunken driving ticket folks that haven't had big losses to charge a premium appropriate to the category.
It would also be roughly the equivalent of insuring a house that is currently burning down - the risk of loss is 100%, so you would have to charge the full value of the house.
Insurance carriers typically assess the risk associated with broad, similar categories (so that the expected loss result can be predicted and those that have minimal losses pay for those that have major ones).
Some choose to insure the more difficult, less predictable, or high insurance coverage amount risks - if they're wrong, they tend to buy the farm. Many companies went broke after hurricanes Iniki and Andrew.
In order to insure in predictably high risk areas in Florida at a lower premium, the company would have to charge considerably higher rates throughout the rest of the state, making those folks cranky.
First of all, you didn't sound like you had much experience with underwriting or with hurricanes.
Building a home that is 'guaranteed' to withstand a Cat 3 or 4 storm would make it prohibitively expensive. Forget computer modelling; when winds get past 120 mph there are too many variables based on individual structures and landscaping. Near or above 120 mph wierd things happen.
Although most believe that the coastlines are the worst, there is significant damage miles inland from hurricane winds and tornadoes. Also there are more deaths and damage inland from flooding than there is near the coast.
Regarding damage and risk assessments, one account I worked was about $138 million and based on my report and assessment the insurance carrier still made money after it was hit by Hurricane Ivan. So I have an idea of what goes on.