Making USB reversible to begin with would have necessitated twice as many wires and twice as many circuits, and would have doubled the cost. Bhatt says his team was aware at the time of the frustration that a rectangular design could have, versus a round connector. But in an effort to keep it as cheap as possible, the decision was made to go with a design that, in theory, would give users a 50/50 chance of plugging it in correctly (you can up the odds by looking at the inside first, or identifying the logo).