That said, this doesn't mean marijuana needs to be recreationally legalized; in the US it would only need to be made a Schedule II drug rather than a Schedule I drug. Cocaine is a Schedule II drug IIRC, and it's routinely used medically, so it doesn't make sense to have recreational legality, or tolerance of widespread use, just to get medical benefits.
For virtually every cause, there are groups "working heavily behind the scenes for decades" -- the existence of activist pressure doesn't seem to correlate with policy change. I'd love to see hard data disagreeing with me, but this is my impression from being an activist for some time, and knowing the histories of social change for various struggles.
That said, marijuana is certainly less benign than you're making it out to be. I know several people who started using marijuana in high school and became interested in basically nothing else. Anything can become addictive, but biological components that have tolerance factors are especially effective because they cause you to increase your dosage over time.
It's not like doctors in the 60's thought that marijuana was actually lethal, though. The propaganda about marijuana has been divorced from truth basically the whole time, but it's been scheduled anyway.
I find it hard to believe that this is simply a miracle story of the long work of activists finally paying off. There are no free lunches. If we're getting legal marijuana, we're losing something else. So what is that?
Well, what else are we losing?
Besides, the current laws are not stopping people from doing it. Most know that weed is something which can be enjoyed recreationaly without risking their health or lifestyle. It doesn't hurt anyone around them, so current law is viewed as arcane and unjust. What benefit are these laws providing to society?
This doesn't follow at all. The downside to legalization of all recreational drugs is minuscule compared to the societal benefit.
There is. And because of it doctors really want to use marijuana derivatives. I know some of the folk running the NHS studies and doing some of the PHD work on endocrine effects.
Here's a couple of recent studies on Sativex.
http://www.gwpharm.com/oncology.aspx
http://www.gwpharm.com/GW%20Pharmaceuticals%20Announces%20Ne...
Also, you have organisations like Law Enforcement Against Prohibition, who have been working heavily behind the scenes for the past decade. http://www.leap.cc/