You could have a cable that is unidirectional, with a bidirectional connector. On a $100 motherboard, who cares if the connector raises the price by another 50 cents?
You can even have a round cable with pins radiating out from the center, and the connector would be concentric circles. Then the plug will always go in no matter what.
You can even have a round cable with pins radiating out from the center, and the connector would be concentric circles. Then the plug will always go in no matter what.