Most vehicular laws are about reducing the risk of injury to all. That is it. You cannot prevent all accidents. But you can reduce the chances of someone being hurt or someone causing someone else to get hurt.
I said that in sheer numbers, more people are hurt from car accidents than motorcycle accidents. Why? Because there are simply a lot more cars on the road and people in cars than there are motorcycles. Motorcycles can only hold 1-2 people, most cars hold at least 4-5, some more. Even trucks can hold at least 2-3 people. But many motorcycle accidents/injuries/deaths are due to other causes as well, such as speeding and/or not wearing a helmet, or worse driving while intoxicated.
What The Latest NHTSA Fatality Stats Reveal About Motorcycle Safety
Motorcycle Accident Statistics and Possible Causes - MotorcycleAccident.org
Don't worry. I support stricter motorcycle safety laws as well though, including mandatory helmet use for all riders.
Now, I don't have an issue really with seatbelt laws as they are now. (I think NH should at least have a law about it, but eh) I only argue that it is not a violation of anyone's freedom to have seatbelt laws even that cover adults. It saves lives. And possibly even
some mental anguish.