If we go along that road, what's next? Should police officers be everywhere, ready to snatch a beer from an adult's hand if he seems to have had "too much" to drink already? What's too much? How do you know? The Nannier a state gets, the closer you are to complete tyranny.
Instead, we could just consider everyone personally responsible for their own choices.
- Didn't wear a seatbelt and got paralyzed in an accident? That's certainly tragic, but you're personally responsible for your choice to not wear a seatbelt.
- Didn't wear a seatbelt and nothing bad happened? Well good for you!