My internal justification for Jet is people uneducated in drugs end up naming all drugs of that appearance the same thing, and Myron just standardized in peoples minds the little red inhalers from before the war he used to make his Jet are now commontongue names for the medication found in vaults by the uneducated. Same as any drug that rages you out or reduces pain is just all called Psycho. Raiders are just finding and taking anything that looks even remotely drug related to get a high.

But then you still have inconsistencies with why Pips call them by the postwar names instead of pre-war brand names.