I'm not going to claim that nobody was ever harmed by cannabis. But it's a cold, hard fact that alcohol causes much, much more harm, both physically and socially. So why does anyone think they're on the side of the angels when they support using the criminal justice system to coerce people who choose cannabis, while accepting that casual alcohol use is a choice an adult is allowed to make without legal coercion?
This was the point of the roads satire. We accept risk as a cost of freedom there.