Aside from just the people who have bought into the scaremongering about drugs, there is a significant contingent of people who see it as 'unfair' that anyone could use a drug and get even temporary happiness. Nothing offends Americans (I simply don't know how prevalent this is in other countries) more than the idea that someone else might be having an easier time than themselves. It's why many would prefer companies to go without substantive punishment for harming many people over having one person receive a large punitive judgement in court cases. The McDonald's coffee lawsuit is usually the canonical example. If McDonald's had only paid the lady actual damages, they would have simply continued their practices and harmed more people. But that is preferable to the situation where that one lady got a 'payday'. Apparently nothing is worse than the feeling that someone else has had it easier than one has had it ones self.