One thing I am mostly against is nationalized property/casualty insurance. California seems to have taken every opportunity to not properly price risk.
My worry is that while extreme, their logic and priorities do not feel unique for government decision making. The last thing I'd want to do is expand it.
When you distort risk pricing, you distort the market, and if you do it hard enough for long enough, you are basically pulling back the slingshot.
While this also applies to mutual insurers, my philosophy is being serious about solvency is the best way to know if you are properly underwriting and pricing.
I feel like the government operates too much knowing that they can backstop it either themselves or by imposing an assessment on the market.
You are right that the really big disasters are very correlated events. While not a silver bullet, reinsurance and other risk transfer stuff can help smooth those kind of events out. The good-ish thing with those risks is that while they are uncertain, they are sort of identifiable, known unknowns in Rumsfeld parlance.
I agree with that sentiment, the thing that always seems crazy to me is that California's housing pricing in the face of all these things, but perhaps it's sort of pick your poison. Like I don't want to harp on it, but the only implicit or explicit thing everyone appears to agree on given the decisions that have been made is protecting housing prices above all else. But don't expose people to the ramifications of the housing appreciation (Looking at you, Prop 13).