What killed legitimate research was the FUD-informed Schedule 1 classification (or similar, outside the US) of the most promising agents in this field.
The point is that big pharma was pouring money into research of these chemicals to use them for treatment in therapy.
The cases of abuse that ultimately led to the stigmatization where blown up because that narrative served the view that the general public had of these substances anyway.
The same rhetoric people use today: "encryption should be forbidden because paedophilia|money laundering|<insert whatever upsets your target demographic most>"
> Not a huge factor really because schedule 1 DEA permits are available. I know a few academics with them.
What good is an permit if you don't have anyone to fund your research? And how do you get research funded for something that can't be brought to market because ... Schedule 1?
Particularly LSD but also MDMA.