Why do people leave the shower stall doors open? Probably because shower stall walls are stupid. Just more stuff to get dirty and require cleaning.
People are not animals, to corral into tiny little stalls or cages or pens.
Tear out those stupid pretend walls, and do a proper communal shower.
But why can't a communal shower have some bench or shelf somewhere, sensibly designed, to put your stuff? And what do you need anyway, that a person can't keep in their locker? A soap dish and a shampoo bottle?
Clothes and a towell, can be in one's locker. Generally shower rooms and locker rooms are connected, so that one shouldn't have to walk naked, for too far. | 
