The problem is we keep using the term health `insurance' when we are not buying insurance, we are buying health care coverage.
As you say, `insurance' is supposed to provide compensation when something unexpected happens - a rock breaking your windscreen is unexpected and auto insurance correctly pays for that event. Let's face it, if your `insurance' covers yearly health checkups and monthly prescriptions (e.g. insulin) then you are getting a benefit, not insurance.
Unfortunately, words have power and the terms we use to describe a thing winds up having a large impact on how we view that thing (abortion vs. choice anyone, why isn't that pro-abortion vs. anti-abortion)