Some of it is basically racist propaganda that entered the public consciousness and became "true".
Hallucinogens though... aren't just drugs that change something a little. They can give people profound religious experiences. Some people become an unsettling kind of prophet for a religion of the drug. In the 60s-ish era there were people that wanted to change the world with the drugs with plans to dose populations and leaders to effect major changes. They are very powerful things and with them minds can be rewritten... any sufficiently powerful tool is dangerous. Some early signals and bad actors (basically parts the drug culture that separated from the early scientists studying the drugs) scared the shit out of many in the established society and the propaganda machine turned on and turned them and drugs in general into an evil.
Sort of a knee-jerk stupid reaction that had some basis in real issues but was distorted and exaggerated by people who didn't know much of anything and just got on the bandwagon. (remind you of any other societal issues?)
Hallucinogens though... aren't just drugs that change something a little. They can give people profound religious experiences. Some people become an unsettling kind of prophet for a religion of the drug. In the 60s-ish era there were people that wanted to change the world with the drugs with plans to dose populations and leaders to effect major changes. They are very powerful things and with them minds can be rewritten... any sufficiently powerful tool is dangerous. Some early signals and bad actors (basically parts the drug culture that separated from the early scientists studying the drugs) scared the shit out of many in the established society and the propaganda machine turned on and turned them and drugs in general into an evil.
Sort of a knee-jerk stupid reaction that had some basis in real issues but was distorted and exaggerated by people who didn't know much of anything and just got on the bandwagon. (remind you of any other societal issues?)