My point is, that a "cyber attack" is poorly constrained, compared to something like a fire or a flood... a company only has so many assets, valued at $X that are liable to be burned to the ground or ruined by a flood, and these constraints can be modeled and adjusted for. Perhaps I am mistaken, I don't see a cyberattack as being analagous to anything else in the insurance industry.
Those are not easy things. People litigate the difference between fire and flood damage all the time. (Putting out a fire normally involves lots of water.) Sometimes flooding in building X even causes a fire in building Y. Is that covered by "fire" or "flood" insurance? The difference between various cyber attacks isn't substantively more complicated than any of the traditional insured risks. The issue is that insurers haven't invested in the experts needed to properly assess those risks. That is their problem to solve, not the customer's.
That's more or less the core competency of insurance providers...