Those are not valid comparisons. The difference is that a seatbelt law only provides safety to the person making the choice to wear the seatbelt or not while the other laws are to provide a safe environment for EVERYONE using the road. That's the whole point of the argument.
If someone chooses not to wear a seatbelt, the only person they are putting at more risk is themself. If someone chooses not to obey a red light, they are risking their own safety and that of their passengers, along with that of drivers and passengers in other cars.
By not wearing a seat belt you are forcing the police and other first responders to clean up your brains and other organs off the road much more often then if you did wear a belt. Its kind of like the law that prevents you from taking a dump in the middle of the road, why does it exist? because no one likes cleaning up other peoples turds just like they dont like scraping their brains off the median.
Helmets wear I live are mandatory on bikes, including ATV's and Dirt bikes off public highways. It just makes sense to wear a helmet and buckle up. I had a ATV accident myself last year and bruised up my pelvis and had a little whiplash. I had a helmet on a my helmet took a big smack and if didnt have it on I would be typing this today with some software like Stephen Hawking uses.