That's why nobody smokes pot, right? ROTFL!
It's also why nobody commits burglary, robbery, assault, rape, theft, etc.
It's difficult, enforcement wise, to ban a consensual 'crime.' Two-thirds of murders (for example) get solved; the fraction of drug 'crimes' that are even detected is assuredly orders of magnitude smaller. This is due in no small part to the fact that murder, unlike drug 'crimes', in and of itself has a victim - who will try to avoid and resist the crime and whose family and friends will assist in its investigation, whereas everyone involved in a drug 'crime' acts so as to make it succeed.
So, you think all consensual actions should be legal, despite externalities affecting others?