The danger of the areas has not been properly accounted for, and now that we have a better understanding, nobody wants to pay what it actually costs (either in increased insurance, which apparently CA has limited, or building design changes - knock down the flammable one and build something impervious, or even abandoning untenable locations - perhaps after disaster, perhaps before).

Everyone's talking about fire insurance, but the earthquake insurance question is even bigger and basically untenable in a worst-case scenario. So in that case, CA wised up and the state is much more earthquake resilient than it was 30 years ago.