Nothing is innocent, tobacco, caffeine, alcohol, car exhaust, fast food, skydiving, not wearing your seat belt, riding a motorcycle and a ton of other things in life are potentially dangerous or bad for you. We accept all sorts of risks to public safety and health and a lot of them are demonstrably worse for you then cannabis and yet society finds a way to navigate those threats without outright banning them completely. Risk alone should not be the only consideration we make in determining what is and is not a legal activity.