That's a great theory. Do you have any supportable facts? Any?
Well, I could also ask to see the proof of the opposing POV's but ....
A very close friend used to work in healthcare consulting for a big 5 accounting firm. Did a lot of feasibility studies for hospitals wanting to expand their services which needed approval from the gov. He told me that if he wanted to work and advance in his field he had better report back that the need was there. Hospitals don't hire firms that tell them there is no need.
I submit a lifetime of seeing/reading media reports concluding, among other things that "a new study indicates that marijuana leads to" a) heroin addiction b) impotency c) a criminal life d) sociopathic behavior e) f) g).... I can't recall even one study that concluded that pot is essentially harmless in and of itself. I'd guess that such studies exist but they never saw the light of day. Politicians who project themselves as being "tough on drugs" don't want the NIH to conclude otherwise.
Someone always has to pay for these studies. No one does it for nothing. If you are a bio-medical researcher dependent on grants that come either from the government or from the medical/pharmacutical industry, if you released a study that supports the use of marijuana to treat things that would render a lot of prescription drugs obsolete, or conclude that sanctions on pot use create more trouble than if they were decriminalized you would have a short career as funding went elsewhere. Do you think the DEA would continue to pay for studies that conclude that the DEA is unnecessary?
I'm all in favor of the scientific method buy it's naive to think that these types of studies are conducted in a purely unbiased way.