You guys will make fun of me but why is this "Women making a sandwich for men" phrase is so popular in USA?
Because women today, think that it is sexist and beneath them to do the jobs and fill the roles that they have traditionally done for centuries, like cooking and cleaning. So bringing it up humorously pisses them off. For the record my wife makes me a sandwich and packs my lunch everyday and has always done so for our 25 years of marriage.