It's a valid political position to believe that people don't need government regulation (laws) to behave themselves, not make mistakes, and not take risks that might lead to mistakes. It's the libertarian/anarchist viewpoint, as mentioned. But that's not how the government in San Francisco, California, or the US works.
Those of us who don't hold to the libertarian or anarchist positions believe that it's a good thing for laws to prohibit risky decisions that are probably going to be totally fine, if the not-fine case is particularly bad. For instance, that's why there are food inspection departments; even if you don't believe anyone is deliberately trying to poison people, there are a set of risky behaviors (not refrigerating things promptly, not washing things, etc.) that stand a small chance of getting people sick, and we believe it's worth stopping those, even if it slows down production, and even if we can't completely eliminate people getting sick.