Saucy seaside postcards never did much to improve the lot of womankind in a male-dominated society. Yes, they sometimes had a pop at men but that wasn't punching down - big difference.
Still, there is often humour in adversity and some of these postcards are very funny and some are quite clever. I find myself disapproving of them and approving at the same time. I think most modern women might disapprove of them but I don't think many would actually be 'offended'.