Some weird Apple marketing strategy (to have different port than anyone else) would be my biggest guess. Also, the USB probably isn't the best choice (as others

Some weird Apple marketing strategy (to have different port than anyone else) would be my biggest guess. Also, the USB probably isn't the best choice (as others mentioned you want to have audio and other stuff in one port).. but Apple was among the manufacturers to agree on the micro-usb just few years back.