I think people underestimate how cheaply products are made. > Making USB reversible to begin with would have necessitated twice as many wires and twice as many

I think people underestimate how cheaply products are made. > Making USB reversible to begin with would have necessitated twice as many wires and twice as many circuits, and would have doubled the cost. Adding more wires, even if it is a few is not the cheapest one and therefore not the one that wins. The relative convenience of a feature is always trumped in early days by cost-to-produce. USB-C recently introducing the symmetry of the connector does not imply that manufacturers will use it... ie you have a symmetric connector that performs differently based on how it was plugged.