Re: Ah, yes. "Capitalism"
Also a car used for hire or reward is likely to be carrying higher risk passengers. By that I mean that they are likely to earn more and thus off work compensation will be higher. They are also more likely to be able to mount a court case. It is the same for normally staid classical musicians. Try playing a violin with a broken finger or a trumpet with a bruised lip - neither injury requires a full blown crash as its cause if you are with a friend (likely to be another musician) in your car.
It is all about risk - actually "what we can get away with" multiplied by risk.