They could've added the extra pins, and kept the square pin count, but then molded the ceramic such that one corner is clipped, then had a socket to match that

They could've added the extra pins, and kept the square pin count, but then molded the ceramic such that one corner is clipped, then had a socket to match that would only allow full insertion if the chip body is rotated to match. Of course, doing all of that would have drove the cost up considerably - for not much practical purposes. No company that wants to stay in business is going to do that, and I wouldn't expect them to.