All right, I’ll bite then. We keep people from forbidding others to cloud their minds (a moral absolute), and we keep people from committing crimes when they do so by punishing them after the fact, thus hopefully creating a deterrent effect (an assumption based on a moral supposition).
No matter what way you slice it the system will be designed by humans and will inevitably be imperfect.
We ultimately would allow more liberty for some than others regardless. I guess I would prefer to protect liberty for those who produce over those who ultimately cause productive liberty seekers harm.
If you propose to protect liberty for those who produce by continuing our current drug bans, I'd note the following: