Not to get off on a "save the children" thing, but I think a part Keith's legacy is the fucked lives of people who saw him and thought there was a certain glamour to being a junkie.
I know what you're saying but the smack mystique prefigured Keith, goes right back to the jazz greats at least, if not Rimbaud and his schtick about 'disordering the senses.'
From what I've read he never seems to have personally played to that romantic notion, he just liked his drugs and drink, it was those around him who bought into that particular line of bullshit, like poor Gram Parsons.