Ok, I get it. If a few people misuse or go overboard with something, and they, or others, are harmed or die, then that thing is undoubtedly evil and needs to be taken from the entire body of the public for our own good - by force, if necessary. So the left - who absolutely loves this style of thinking - must be correct about a few things that also fall into this category:
Fast food
Guns
Capitalism
Religion
Freedom
We'll start with this little green plant and see how it goes from there. Y'all with me?
You already can't legally use cannabis and an officer would take it away if they did see you using it.
This stuff affects others as well, so the issue goes beyond the individual.