They don’t care if it causes brain damage. It’s invisible to the user for the most part. The rest of us suffer, but the user doesn’t give a damn. They get off on it and that’s all and I mean ALL that matters in life for them. The lies and justifications and utter insanity flow from the use quickly.
Alcohol isn’t good for you, but it just doesn’t screw people up at low to moderate intake. At least not mentally. Pot even at low use changes a person. They might even think for the better. A more ‘open mind’ and so on. But reality is very different from their deluded and fooled mind.
In the coming new world they need to keep the peons under control. What better way then sex and drugs.