In my opinion, Insurance has lots of paper-work and is a time-sink because the insurance brokers/companies needs to do lots of due diligence to determine the counter-party and the risk at hand. You are selling something that could potentially be worth $100k for $300/year, you better be right that the litigation is not happening, at least not that often.
These guys do not do that, and it is not clear how they do for the counter-party risk and insurance fraud. Instead, for now, they'll just accept their friends who have a common risk-profile and are easier to serve/predict their liability. After they raise a few rounds, they might get to the actual problem and try to solve it.