> you're assigning a value to a thing beyond it's market cost and saying everyone is in fact a winner
Of course. If that weren't true, people would not buy insurance.
> Risk pooling via a private insurance company is negative sum
If you only consider monetary costs and benefits, yes. But this ignores the (non-monetary) value to the insured of not being exposed to the risk (because that risk exposure has been transferred to the insurer).
> That should not then be taken to mean it's a bad deal (it isn't).
I agree that it's not a bad deal; I'm just saying that the reason it's not a bad deal is that people consider more than just monetary costs and benefits.
For the first part you're assigning a value to a thing beyond it's market cost and saying everyone is in fact a winner, and that's a little strange. Risk pooling via a private insurance company is negative sum because someone makes a profit beyond their costs. That should not then be taken to mean it's a bad deal (it isn't).