At that time, the symbolism of appointing a woman the Supreme Court was considered important.
Similar to how Joe Biden pledged to have a black woman appointed, which is how we have Ketanji Brown Jackson on the Supreme Court.
As I recall, the liberals of that day liked to say that Republicans were racist and sexist and all that. They still do. But Reagan’s response was to appoint a woman to the Supreme Court, which was apparently supposed to make the point that the Republicans weren’t sexist.
So there you have it. Republicans can do affirmative action type appointments as well as Democrats.
That’s nice. So we got a mediocre mind, and a liberal to make a point. All because she has the right plumbing.