Ford did that because they were mass produced so cheaply....Pintos, MustangII's, etc....they were mass produced on a epic scale. Sometimes, they were done so fast, the deck surfaces weren't flat, and the align bore on the mains were out, motor would heat up and go away. Under warranty, they'd just throw another boat anchor in there....
Those little motors once you skinned everything and trued it all up and rebuild it, it was tough as nails. We used to commonly throw 16 to 21 Pounds of boost to them, ran like a scoulded dog. Hit 22 PSI, made a nice little handgranade