The First Order makes it a point to treat its male and female Stormtroopers the same in order to enforce conformity. Everyone gets the same uniform (obviously) everyone bunks together, showers together, gets the same haircut, etc. There are some things that are sex-specific (for example, men need to learn to shave their faces) but these are kept to the minimum.

After Finn deserts to the Resistance, he's introduced to gender norms, and he finds them absolutely baffling. Why do women shave their legs? Why can't men wear dresses? And so on.