alt Hacker News> Not enough money in it
Source?
The simple answer seems sufficiently explanatory. Psilocybin is burended by its history as a recreational drug. That creates pockets of motivated advocates against it in a way that doesn't materialise for most drug candidates.
Adderall is just speed, which also has a long history of recreational usage. It was a widely used recreational drug decades before it began being used for ADHD.