One day I was flying somewhere and the plane encountered turbulence. The seat belt sign came on, the Captain made a P.A. asking everyone to buckle up, and the flight attendants came through to check. So I overhear this woman behind me say to her seatmate, "Aren't you going to fasten your seatbelt?" And Ms. Einstein says, "No, I'm not worried about it. I guess I'm just a rebel!"
So happens I spent 8 years in airline emergency response and worked more than one event where 'rebels' like her ended up ricocheting off the ceiling, seats, walls, and other passengers in severe turbulence. Broken bones, a broken neck once (with paralysis), cuts, bruises...and of course, the inevitable lawsuits faulting the airline because somebody didn't have the sense to buckle up.
If you've never been in a vehicular collision, you can't begin to understand the forces your body is subjected to. Wonder what the seatbelt law compliance rate is for people after they've experienced a serious accident? Pretty high would be my guess.
Wearing your seat belt in any kind of vehicle is such common sense that the worst part of this whole debate is needing a law to begin with.