This is not only smart engineering, but a huge cost savings too. Crank out hundreds of thousands of the same part number after a robust process is established and you're making money and a quality product. Don't change just for the sake of change. This also helps lower the dealers' cost since they don't have to stock 20 different oil filters. Kind of like Chrysler in the early 70's when the same starter fit almost every engine and model. This is the anthesis of Ford who may have three running changes of the same part in the same model year and none are interchangeable.