pizza comes in a square box because its way to hard to make a circular box and it takes too much material. seriously now...
yogurts you eat, with a spoon. kifers which are thinner, like milk shakes and smoothies, you drink. yes boxes that can be shipped flat and take up less room to store that way, and then folded into the neccessary box shape by hand, only when ready to use, are of course much easier to do rectangularaly. round or relatively rounded, say octangular boxes, arn't that difficult to have folded by machine but would involve a much more complex folding pattern to ship flat and fold by hand when needed. obviously boxes of much more creative shape, virtually any shape, can be (and ARE) MADE, but this would be much less practical for your typical franchise pizza joint. well i don't remember the last time i ordered or ate pizza. not my favorite food like substance. i prefer noodles, and no crust thank you. =^^= .../\...
i'm guessing you and a few others TOTALLY missed the 3rd line of that post - where i said "that makes no sense whatsoever"