I'm kind of tempted to write this thing where the Wraith have their own version of PETA, who argue that no, really, humans have a soul, too, you shouldn't eat them! And everyone thinks they're totally crazy, yeah, right, they can't even communicate properly, no telepathy at all - sure, they build pretty cities, but so do ants - and anyway, that human-less diet, that can't be good for you in the long run...