[cool_dude85]

Insurance in general is more heavily regulated than this. There are a few reasons: because society doesn't want these companies racing to the bottom on price and leaving their customers high and dry when the catastrophe does hit, because society finds insurance pricing based on certain personal aspects, such as race, odious, and because the government mandates some types of coverage and they don't want to let insurers rinse customers that are forced to buy their product.

For all these reasons, insurers typically must justify rate increases.

[twoodfin]

While it’s certainly accurate insurance is a regulated industry, nothing you listed explains why it’s a good idea to allow government to set or approve rates vs. ameliorating those social concerns through other means.

[20after4]

Because insurance isn't optional. If the law demands insurance then the law must assure equal access to the legally mandated insurance.

[twoodfin]

Which law demands home owners carry an insurance policy?

[Kalium]

In the US, it's a requirement of mortgage lenders. This makes it less of a legal requirement and more of a de facto requirement, as most homes are purchased via mortgage in the US.