I was wondering the same, tried to find the reasoning but couldn't. I guess it's one of the many examples where public policy doesn't match the science. With all the risks considered, LSD should be treated the same way as weed is. It definately shouldn't be in the hard drug category with heroin and cocaine.

Even more, alcohol is way more damaging and dangerous both to an individual and the society. But historically we are okay with alcohol, while drugs are assumed to be way worse.