I respect your opinions, and unfortunately it is true that until recently law enforcement and hospitals didn't keep good records that could help prove or disprove the benefits of helmets. Without good data, the statistics can be and are constantly manipulated to serve the purpose of the one's doing the manipulating. As the old saying goes, "figures don't lie, but liars figure". I'm reminded of all the credit folks were taking recently when highway fatality numbers were released for last year, showing another significant reduction. The governor took credit because of his directives to the state police to increase highway patrols. Local governments took credit for their safe driving classes. The list of credit takers was extensive, so I won't list them all. Unfortunately, very few in the media saw through all the BS and came up with the real answers. Drivers aren't any better than they were before, the number of incidents keeps going up. Fatalities are down because cars and trucks have gotten exponentially safer over the past couple decades due to mandated safety features, with things like airbags, seatbelts, stability control, crush zone design, etc., making what used to be unsurvivable crashes very survivable. If everyone fought as hard against all of those safety improvements as motorcycle riders do against helmets, I'm quite sure we wouldn't be celebrating reduced fatalities on the highways.
As for the cost to society, if you really believe that everyone has gold plated insurance that will cover that lifetime of care and the lost income to support the family, I respectfully submit that you are living in a fantasy world. There is a large and growing percentage of the population that has no medical coverage whatsoever, and another even larger percentage that has fairly basic coverage that tends to be cancelled at the whim of employer's and insurance companies. As in, file a claim, lose your coverage. And many of those policies have upper limits on lifetime benefits, they don't just agree to pay forever. And then you have the actual motorcycle insurance policy. Read your policy, I don't think the medical cost coverage on most policies would cover a week in the hospital, much less a lifetime. And that's on the good policies, not the ones that young folks on a tight budget tend to have. Minimum coverage requirements in many states are laughably low, and there are a lot of folks who opt for that minimum coverage.
If the available evidence, statistically shaky or not, doesn't convince you, or if common sense doesn't convince you, and you still don't want to wear a helmet, then don't wear one. When, and I'm convinced it will just be a matter of time, the Fed's force all the states to require helmets, don't be surprised when you get pulled over and ticketed, or when you lose the privilege to drive on public roads after several tickets don't convince you. Note, you won't be losing any rights, you will still have the right to not wear a helmet. You will just lose the privilege of doing so on public roads.
Jerry