Obese people, for example, use more medical services than fit people, but we don’t charge/tax them more. This suggest that it is not okay to discriminate against the obese (which is generally a voluntary condition), but it is okay to discriminate againt being young and male (which isn’t a voluntary condition).

“young male should pay proportionately more”

This is always a fun topic — the fact that we are allowed to discriminate against some groups but not others, and that this distinction appears relatively arbitrary. Why do fat people and females of breeding age not have to pay more for health insurance? How come only older people have to pay more, or why do older females, who have less health complaints than older males, pay the same amount? etc.

I think the real problem is that groups that complain a lot get special status versus those that don’t, and if you wanted to tax dangerous cars more, you would get a lot of complaints and no politician would have the will to do it.