Not going to argue. Still going to say it's stupid. Especially the fucking morons doing it driving. Those fucks should be in jail or at a minimum not allowed to drive for a long time. That is just retarded.
I had a friend that was smoking pot while driving with me in the car without even telling me. He said "its fine, its not like its alcohol". This fucker was using a massive ass pipe and holding the wheel with his leg going 50+mph when he just pulled it out and I had no idea he would do it as he never had before. I stopped riding with him after that. He wrecked ~3 cars after and luckily he was the only one that got a little fucked up.
Also, Yeah, alcohol is bad too. Don't do that shit. Especially don't do that shit and drive.
Caffeine is a drug, much of the world population is hooked on it and using it daily. Some drugs have more downsides/problems than others but anything taken to excess or done in stupid situations is a hazard not just to you but others and should not be done.