I know little to nothing about most substances, but I've read a bit about the origins of marijuana prohibition in the US and the current state of affairs. And I think there is one answer to your question of why are the governments so afraid of them which us, bitcoiners, can understand easily.

I think one of the reasons that explains why weed is mostly outlawed, while the seemingly comparable alcohol has a full green light from the government, is that the production of the former is highly decentralized, while the latter is highly centralized.

There is a lot of big money behind alcohol. It's pretty much an oligopoly on the western countries and the third world as well (every other south east asian beer brand is basically just Heineken relabeled). These guys are willing to invest plenty into lobbying. And they wouldn't like people to easily access weed since that could hurt their sales.

On the other hand, marijuana can easily be grown by anyone at home with very little knowledge and resources. It tends to decentralize: the moment "big" marijuana producers would get too greedy, produce too low quality or just offer the market a bad service somehow, people would easily retrace to growing it at home. Damn, I'm sure a lot of people would always grow it at home in the first place and never rely on companies to grow it for them.

So, I think this is just another instance of the pattern where you have a very reduced group of people (the alcohol lobby) who can benefit incredibly from a favorable regulation, while you have a very large body of people (weed consumers and potential consumers) who are affected negatively by that same regulation, but only subtly at the individual level. Because of this, big alcohol is willing to get active and visit Washington as much as needed to keep weed illegal, while on the weed trench, nobody has a billions-strong incentive to go and mingle with the regulators.