The point of that line of reasoning is not that drugs should all be legal; rather, it is that the current laws are not based on health (and the assumption is that it should be). Drugs that pose some of the most serious health risks, alcohol and tobacco, are legal and can be purchased without consulting a doctor, even by people who are killing themselves with their habit. Drugs that pose less of a health risk like marijuana or psychedelic mushrooms are completely banned. Moreover, illegal drugs, like illegal alcohol, have unknown doses and may have unknown impurities, or may even be a different drug than what the seller claimed.

Anyone who knows the history of the war on drugs knows that public health is a cover story. The first drug laws in the USA were bans on cocaine and heroin, and the arguments presented to Congress and the general public were overtly racist. It was said that cocaine turned black men into murderous demons who could not be stopped even after being shot in the heart. Heroin, besides being made by a German company, was also said to be popular among Asian immigrants who were bringing their awful habits here. Then marijuana was banned, because, according to the testimony given to Congress, it fueled jazz music and caused white women to want to have sex with black men, and Mexicans were using it to corrupt the white youth. Drug enforcement has always disproportionately targeted black people.