I've always thought that ethically "right" forms of insurance (and other financial products, like equities, futures, etc.) is that they should enable individuals to take actions that are riskier than they would normally be able to, without unduly increasing the aggregate risk of the entire system. Of course, this is 1. Hard to measure and 2. Hard to define "unduly". For example, I believe mortgages are a "good" financial instrument, because they enable people to have homes and roofs over their head without introducing systemic risk... except when done in 2008. The devil is in the details and the implementation, I suppose.