Keeping the conversation within the domain of the current article, there is no policy goal to mitigate harm from recreational drugs. If a drug makes people feel good it will be outlawed whether it is completely harmless or very dangerous. This has the side effect of pushing some people from relatively harmless but illegal drugs whose effects are well understood to potentially harmful new drugs that are not yet illegal.
No lives will be saved by this policy, which isn't surprising since the goal is not harm mitigation (despite the rhetoric of government officials) but keeping people from consuming psychoactive substances that make them feel good.
Are far as FDA regulation vs. liability is concerned - you cannot outlaw the production of drugs which will kill some people. All you can do is provide incentives for drug makers to research the risks of their products as thoroughly as possible. Drugs are still approved by the FDA that kill people despite the fact that the FDA approval process is stupidly expensive.
There is no perfect world. The goal of policy should be to reduce risk in a cost-effective way. Harm reduction should be balanced with the corresponding damage regulation does to life-saving medical research. After we weigh various policies we may find that the status quo is suboptimal.
As rational people we should keep our minds on the right trade-offs and the right metrics. Many people are comfortable with the idea of a regulatory state regardless of its effectiveness - it makes them feel safe. We should not let these emotions of safety influence our thinking overmuch.