I'd rather the law be more around information than control. If one believes in the idea of freedom and liberty in the US, then one should support a model where individuals are allowed to make their own decisions, but ensure the facts around such substances are well researched and publicized.
Alcohol kills, and yet is not actually very well controlled at all. Marijuana doesn't kill anyone directly, and yet the lies told about it has kept it tightly controlled, even as the real facts continue to come out.
I don't believe the government really has any obligation to keep us safe from our own poor decisions, assuming those poor decisions can be argued to be have been informed using truthful information.