i agree with you to an extent
its also coz of the obvious thing that women aren't expected to be able to work in teh fields etc as capably as men..
they said it wasn't so much the carrying of the name that mattered but more the fact that the women move away from the family to live with their husband's family, so that m eans that their own family loses a child carer, cook, cleaner etc etc
and you're right, it has to do with the name as well - the woman who was the main journo in the doco said that its more about gaining a reputation/prestige for the name than the maintaining of the name and since women don't/didnt generally aim for or could afford a good job or education, you couldnt really elevate your family name.