I'd say you're dead wrong here - just look at the pushback against seatbelts when the laws were introduced. Look at the devices on sale, today, to defeat seat belt alarms.

Regarding your second point, that's also objectively incorrect. When accidents happen, passengers, especially backseat passengers, become projectiles that cause additional injuries or excess deaths for other occupants. It's not just the dude not wearing a seatbelt dying, it's also the people around them.