Tat is one of my questions precisely. Gender roles in general are qidespread among cultures.
I think it is reasonable to say patriarchy and male disposability are two forms of discrimination based on cultural beliefs about the gender.
This is why I find it polarising and jumpy to conclusions to think all gender roles come from patriarchy, we dont really know. As far as we tell, this are just some among many discriminations based on gender.
Do you get what I mean?
Agreed that we should not jump to the conclusion that all gender roles come from patriarchy. But I think it is reasonable to recognize that many do seem to come from patriarchy -- or, at the very least, they serve to support patriarchies.