You're making an argument for which anything could be illegal. The public could develop an irrational prejudice against people wearing purple. Then you could make all of those statements about that. Is it the public's right to ban purple clothing? Do we still have freedom simply because there is more than one other color? This may seem facetious but it's not that far from tattoos and piercings. You're almost suggesting that there shouldn't be inalienable rights. I understand that in "reality" there ultimately aren't but I hadn't realized our society was so ready to abandon the ideal.
Can we force women to be on birth control until they're married and/or have "enough" money and/or fulfill some other arbitrary criteria for having kids? Society -- statistically speaking -- has to pick up the tab for kids born to lower income single moms through WIC, food stamps, etc. That's clearly something that society has an interest in and thus a right to control/regulate right?
If you disagree with the above statement please address it as a matter of far-reaching prinicple rather than as a matter of pragmatics. Our society is ostensibly, largely built on principle; it's illegal to murder because nobody wants to be murdered. This is very straightforward. If we concede that society has an interest in how people interact, truly what is off limits?
Humans are social creatures; they are interdependent cogs in a machine. So as an overarching principle, society is entitled to regulate to interactions between people. To make that bearable, we recognize certain "fundamental rights" that society cannot infringe. Procreation is a deeply-held one, which is why society cannot force women to be on birth control. Taking drugs is not one of those rights.
"The public" may wish to eliminate all mind-altering substances, but the allure of altering the mind is strong, and the enormous contingent of people who desire to consume is going to have to be repressed.
The argument about family and relations, for example, is not so straightforward. What's preferrable, a dad who smokes cannabis or a dad who's in prison?
drug prohibition laws represent something else. they represent the power of the state, and all the inherent violence that goes along with that, bearing down on those that choose to use legally proscribed drugs.
I hope you have a full understanding of what you're saying. legal prohibition implies state sanctioned violence.