You can think of an insurer as someone who provides a service of pooling resources together to help those who got unlucky.
That service is worth something and is not necessarily predatory.
I think the idea of that service being all three of mandatory, not owned by its participants, and profit-driven is what causes it to feel inherently predatory -- that there exist companies which take on risk on behalf of entities who cannot take on that risk (and therefore must participate), and then profit by charging those entities more than they are expected to cost and using the pool of wealth created as investment funds for which only owners of that company derive benefit.
The service is obviously not worthless--some entity has to assess risk, coordinate, and administrate--but it is predicated on terms that make it (I would assert) immoral to transfer more than is necessary from those that participate in the service to those that own the service.
The service is obviously not worthless--some entity has to assess risk, coordinate, and administrate--but it is predicated on terms that make it (I would assert) immoral to transfer more than is necessary from those that participate in the service to those that own the service.