I wonder if that was because in the very early (punch card) days it was not uncommon for women to be employed as "coders" literally typists who would transcribe

I wonder if that was because in the very early (punch card) days it was not uncommon for women to be employed as "coders" literally typists who would transcribe code onto cards from written code sheets prepared by programmers. It would be natural for many of them to learn how to program from reading so much code.