While this does seem like it's true [0], at least in that case the other passengers know whether or not you are wearing a belt, and can, in extremis, choose not to ride with you (I'm going to ignore minors for the moment as that is a different and much more nuanced topic). When it comes to drunk drivers, other people on the road don't even know they are taking the risk. And of course, that ignores the fact that seatbelt laws do not differentiate between when you are driving alone (extremely common in the US) vs. with passengers.
