“I have watched them unload inedible bluefish by the ton”
Blues are strongly flavored but nowhere near inedible. You may be thinking of Menhaden (aka Mossbunker, Bunker), a prolific forage fish that is definitely inedible.
Try Bluefish broiled with garlic breadcrumbs and lemon.
I have, and smothered in Italian Dressing over the grill. I know what blues are and have tried to eat them a number of times. They are inedible.