First of all, gender distinction is very important in the universes of husbandry, hunting, and show-animal breeding. IT makes a different if an animal is a sow rather than a boar, or a dog is a bitch or not. In the days when more people had a hands-on relationship with raising animals for labor or food, the language reflected their efforts and concerns.

In human occupations, it is often meaningful information as to whether a person is --for example--an actor or an actress, a dom9inator or a dominatrix, and in some contexts, a chairwoman or a chairman, a masseur or a masseuse.

This does not make any of these words inherently belittling. If they are USED to belittle the problem is with the small-minded user, not the nature of the words themselves. It is easy to get entirely too precious and find offense where none has been placed.