> I was actually talking about the chemical mixes that are actually toxic / poison that are being brewed in trailers in the rural areas or kitchens in apartment complexes. I wasn't writing about addictiveness.

Right. Well, legalization will help that as it is, in fact, illegal for a legitimate company to sell some unknown poison when it is claiming to sell drugs of a given composition and purity. Also, meth labs as we now know them will become economically impossible if it's possible to get meth legally: They are the perfect, absolutely perfect example of the kind of high-risk/high-reward behavior that is only worthwhile if you have gigantic margins subsidized by the DEA and local police.