It is a little piece of funny patriarchy that men find being called something feminine insulting. Hamlet calling his stepfather “Mother” is meant and understood to be a challenge. However, if Hamlet were to call his mother, “Father,” it would just be odd.
I love the meme going around that has pictures of men doing jobs like firefighting and astronauting…and then their name, age and “firewoman” or “spacewoman” as well as a quote implying that the firewoman understands that firewoman includes him too.