Very good question!
I always wear my seatbelt but not due to the laws. I do it because I value my life and would do it even if it weren't the law. As for airbags, I occasionally meet a person who does not care for them but I would never buy a new car without some form of side-impact airbag.
The seatbelt laws that many people I speak with so dislike come from the 1950s and 60s. The post-war boom was in full swing and the number of vehicles on the road had never been so high. That combined with vehicle speeds that had increased dramatically over pre-war vehicles and safety aspects were practically non-existent was a recipe for disaster. Every year, the death toll on American highways hit a record high. Car companies had tried to market safety packages but the core problem was that Americans did not want to admit that their cars they so loved could very well kill them. Putting on a seat belt was a reminder that the task they were undertaking was indeed very dangerous. Safety didn't sell; just ask Ford who offered a safety package in the late 1950s. It included lap belts, a padded dashboard and steering wheel as well as rubber-edged window cranks. They received very few orders for them and scrubbed it shortly thereafter. As the death tolls continued to climb, the people demanded something be done and Ralph Nader released 'Unsafe At Any Speed', a book aimed at the dangerous nature of the automobile.
The federal government, responding to the outcries of the citizens, made a series of deadlines for auto makers to meet. Crash test standards, 3-point safety belts, crush zones, 5-mph bumpers, and eventually airbags were a result of political push and citizen outrage. It's hardly fair to pin all this on people who didn't feel comfortable wearing a seatbelt 50 years ago. Those older cars were death traps as it was. Metal dashboards, no crumple zones, a lap belt if you were lucky and it was a coffin on wheels. The safety movement within the auto industry was a team effort. The car companies needed to build safer cars and their drivers and occupants needed to take advantage of the safety features provided to them. Every year, seat belt usage increases to a new high and the death toll drops a little more.
Coincidence? I think not.
But if you need further proof, you need only visit your local classic car dealer. Today I sat in a 1956 Chevrolet Bel Air coupe. The steering wheel was huge, easily 18" across, no seat belts, metal dash board, and the window cranks are just begging to be hooked by your clothing in an accident. I stepped back into my 2004 Hyundai Santa Fe which is a padded cocoon, willing to sacrifice itself for me if so needed. I have four airbags, 3-point seatbelts with pre-tensioners, a padded dashboard, four-wheel power disc brakes and less bright shiny chrome. A safer car, indeed.