As long as drugs are illegal, whichever drugs are easiest to make with legally-available materials will become popular, no matter how bad they are or what they're usually cut with.
Make drugs legal, and drug users will return to the classic drugs (pot/coke/opiates/hallucinogens). They'll only use other drugs if they provide a better high or less risk, which to my understanding meth does not.
Imagine a pathologically idealistic, anti-religious, culturally-relativistic, iconoclastic, socially-irreverent, sociologically-progressive signature line here. Or don't.