He may never need a helmet, but it was his choice. There’s something important in that, that someone has both liberty and individual responsibility. It’s unfortunate that he died, but the right to live as he saw fit is an important one.
I agree with your sentiments and, as another Freeper suggested, you should be willing to pay extra insurance or taxes to reflect your belief because everybody else, to the reasonable extent possible should not have to bear the brunt of the costs of your decisions.