As always, loved this piece!
Apparently it's an age-old tradition, dating back at least to the Canterbury Tales, where Chaucer acknowledged that Wife of Bath was a good businesswoman but also portrayed her as greedy and sex-crazed to get some laughs: https://flowerchild.substack.com/p/what-they-didnt-tell-us-about-medieval. Also, back in the Middle Ages, women did most of the accounting and bookkeeping, so math was considered easy and beneath the Important Man Things that men were doing, like philosophizing.
Bummed to hear that about Seth Meyers — I've liked the little bits of his show that I've seen. I hope he gets the message.