Laws against murder serve to protect other people from would-be murderers. The act of murder, essentially without exception, impairs another person's right to live.
Laws against drug possession protect exactly whom from exactly what? It would seem that the essential desired protections could be provided by less restrictive laws. For example, if the goal is to protect people from the hazards that stoned drivers would pose, pass a law against driving while stoned. If the goal is to protect people from having people pushing drugs on the schoolyard, pass a law against open-air sales and sales to minors.
Nearly all of the problems "caused" by drugs are the result of overt acts. As such, laws against such acts may be enforced without the privacy violations necessary to enforce statutes restricting covert acts.
And it would be...okay to violate someone's rights? Or is it wrong? Maybe even morally wrong? ;)
Like I said, I'm not unsympathetic to the article or its goals, but this notion of attacking laws based on morality is just nonsensical. Even in the example you give, it is implicitly understood that it is morally wrong to violate another's right to live, which is what justifies a law against it.