There's much insanity and cruelty that's done in the name of fighting drug use.

I don't think restricting sale of medicine that is often used to make methamphetamine is one of them. Back when it was over the counter, how much of the profit from selling pseudoephedrine decongestants was really profit from selling a meth precursor?

Private profits from legal meth seems like a problem any society has to deal with.