Cost
Saved you a click
I get not making it reversible. I also get making it roughly rectangular.
What I don’t get is making it look symmetric from the outside. It could’ve been made trapezoidal instead, so tactile feedback is enough to know the right position.
It could have still been rectangular. All they really needed to add was a key to the housing of the connector. (Logic being that an odd shaped metal connector would be just a hair more expensive to manufacture than just adding a key position to an injection mold.)
Trapezoid or key, it would have still been a pain when trying to insert the connector blind. Having fingered thousands of different connectors (lulz) over the years, it is still difficult to feel the orientation of a recessed female plug, regardless of its shape.