James Parker, who wrote a great book about Henry Rollins some years ago, directs me to his own piece on the hipster metal phenom and makes this "etymological observation":

"the first time i heard the term - was referring not to the Wire'-reading avant-gardeists but to bands like Early Man and the Sword - trad metal, vintage metal i call it - who had been signed to Matador; the suspicion being that they were somehow using the old metal tropes dishonestly, to wow the indie kids (though both of those bands, as far as i can tell, are absolutely diehard Sabbath-heads). the culmination of that perceived tendency i s'pose would be a band like Wolfmother, who do seem a bit, uh, metallically disingenuous."

i had no idea that Matador was an early adopter in this area...