Do you have any idea of how hard it is to build a USB device? You won't get away without using a dedicated chip + a microcontroller. The parallel port may be old and not work on new OSes without hack drivers, but it still has it's good uses since it's about 100 times easier than using the USB port. For people without lots of experience in EE who are trying to build their own hardware for interfacing to old consoles, that matters a lot.

// Bananmos