Don't even start that shit.
Due to Harry Anslinger and Ronald Reagan, marijuana remained illegal because they thought it would curb the amount of Mexican immigrants coming in which were bringing pot in with them. Also he wanted to build up his government agency, the Federal Bureau of Narcotics. And he realized cocaine and opiates being illegal wouldn't be enough to build his agency, so he worked on making pot illegal at a federal level. There were also many corporations benefiting from pot prohibition. Timber companies supported it because they didn't want to see hemp paper compete with them, racists supported it because it gave them another reason to arrest Mexicans, and chemical companies such as Dupont supported it because they wanted to see medicinal effects of marijuana eliminated as competition, as well as hemp, which competed with nylon and other fabrics.
So you see, it has nothing to do with the effects on people or their health. As much as you'd like to think big brother is looking out for us, they're still looking out for big business' personal interests. Even in the case of marijuana.
“Marijuana is an addictive drug which produces in its users insanity, criminality, and death.”
“There are 100,000 total marijuana smokers in the US, and most are
Negroes, Hispanics, Filipinos, and entertainers. Their Satanic music,
jazz, and swing, result from marijuana use. This marijuana causes white
women to seek sexual relations with Negroes, entertainers, and any
others.”
“You smoke a joint and you’re likely to kill your brother.”
^^ Just some propaganda for pro-criminalization of pot from the mouth of Mr. Anslinger himself.