Isn't this all related to buttons?
The reason why the side that buttons on differs for women is that historically, buttons were moved to the left on fancy clothing because it made it easy for the person dressing the woman to do so, as an affluent woman would have staff who would dress her.
Eventually all makers of women's clothes adopted this because of the association of being fancy, even if they weren't.
While zips may have somewhat adopted this, I'm not really sure they have ever carried the same association, so I don't think it really matters what side the zipper does up. Ultimately, unlike buttons, once a zipper is done up, you have no idea what side it is on.
The reason why the side that buttons on differs for women is that historically, buttons were moved to the left on fancy clothing because it made it easy for the person dressing the woman to do so, as an affluent woman would have staff who would dress her.
Eventually all makers of women's clothes adopted this because of the association of being fancy, even if they weren't.
While zips may have somewhat adopted this, I'm not really sure they have ever carried the same association, so I don't think it really matters what side the zipper does up. Ultimately, unlike buttons, once a zipper is done up, you have no idea what side it is on.