I recall reading somewhere that Fanny Farmer and her eponymous and illustrious (read:nefarious if you're a baker) cookbook heavily influenced American (home) bakers to move from measuring flour by weight to measuring by volume instead. It's done such a disservice to the bread world here in the states. I suspect this is where the need to sift has stemmed as the amount of sifted flour in one cup can be drastically different from a packed cup.
I definitely ignore any cookbooks (with bread and pastry) that measure flour by volume over weight. It's just sacrilege.