Any study like this takes a very narrow view of good vs bad. Can we even begin to quantify how much
good alcohol has done? The amount of fun and sociability it contributes to is staggering. Same with marijuana and no doubt other drugs (i have basically no knowledge of the upside of hard drugs so can't speak to it, but if you google Benzidrine there is an Atlantic article that mentions amphetamine and some upside).
I don't disagree that there are vary bad sides to drug use, same as for driving, soda pop, cheese, whatever. But we shouldn't pretend in a vacuum that there are not also positives, and short of severe societal consequences (like with some hard drugs, perhaps) people should generally be able to choose for themselves