Money. Plain and simple.
In 2013, 17 states in the USA had medical cannabis programs. The Medicare system spent nearly $165M less in prescription medication costs for patients that qualified for Medicare.
The people using cannabis are only a small percent of the population, most still won't use it because of it being Federally illegal. Once federal restrictions drop, usage rates will increase dramatically.
So, if all 50 states had been cannabis friendly in 2013, an estimated $500M less would have been spent federally on prescription drugs. Can you imagine what those numbers will be when you add in all the doctors visits that aren't happening?
Add in private insurance info as well.
The pharmaceutical companies stand to lose Billions of dollars a year to home growing and using of cannabis. It's just too easy and too effective. :D
