I think 'vast majority' of drugs is overstating it a bit, but still - I very much understand where you're coming from and do not disagree.
I regret saying that "Opiates are actually quite safe, as drugs go." I think it has some validity in it's hastily-written context, mostly concerned with countering the article author's cluelessness on his subject. In moderate dosage and without mixing substances, it's basically true - though I'm admittedly coming at it from the perspective of a long-time recreational drug user, hardly that of an upstanding mentor to the young and impressionable here. It's obviously a reckless thing to say in any context, and I would certainly hope that no-one takes it as guidance.