Where your comment went wrong was in conflating rational decisions made at the time the rules are made or enforced with routine rational choices made constantly by the population. It’s much easier to have a rule which says “always wash your hands when preparing food” than to have every single restaurant worker have to reason about the level of risk posed by what they’ve done since the last time they washed their hands. In particular, think about how many bad calls are made by people who believe they’re acting rationally but are acting on incomplete or bad information.
Libertarianism involves a state as weak as possible so it critically depends on people to individually make good choices for a society to be an appealing place to live. You can sue your neighbor if he burns old tires upwind but you’re really hoping he’s smart enough not to because that’s tedious, slow, and risks retaliation. If you don’t have the equivalent of Social Security forcing people to save for retirement, you have to make your peace with having destitute old people on the streets, etc.
