It’s tempting to blame modernity for the abomination that is the bran muffin. Dry as dirt (though nowhere near as tasty) bran muffins have been impossible to get away from since at least the late 70’s. There’s an artisan bake shop not two blocks from here that sells only one kind of muffin — one kind! — without some whole or alternative grain additive. Blasted hippies!
Unfortunately we can’t blame the boomers, at least not completely, for the “health” muffin, since even the very earliest muffins were made from whole wheat, rye and — the miracle food of the age — Graham flour. It seems even a hundred years ago people viewed the morning muffin as a (mostly) painless way to kick start their digestive tracts.