You are dead on about big pharma. That's why Insys Pharmacuticals spent about $500k fighting legal marijuana in Arizona. And that same company got approved for synthetic cannbis drugs: https://www.washingtonpost.com/news/wonk/wp/2017/03/24/a-pharma-company-that-spent-500000-trying-to-keep-pot-illegal-just-got-dea-approval-for-synthetic-marijuana/?utm_term=.611c7e9a6015

"It's dangerous and you shouldn't use it, unless you buy it from us, then it's okay."