But to address your point directly,
“Presumably people’s roles have changed somewhat as we moved from a nomadic society to an agricultural society and from an agricultural society to an industrial society.”
True, people’s JOBS changed, but it was generally always the men that were the hunters, the ones who were plowing the field, or the ones going to the office. The women were always the ones caring for the home and the children, whether they were beating clothes on a rock down by the river, or hitting the on button on their washing machines. The jobs may have changed, but the roles have not – and that’s just the nature of humanity. The proof is anthropological and historical. It spans all racial, continental, and cultural divides, it is not simply circumstantial. The emergence of women taking on men’s roles en masse is a very new and somewhat isolated phenomenon. It is of no coincidence that the push to have women take on men’s roles in our Orthodox Jewish culture happened at the exact particular time and place in history as the former. Our culture is particularly porous to out environment these days, and this is an obvious side effect.