what’s-in-a-name – we didn’t have locks on any of the rooms upstairs (apart from the bathroom obviously) when I was growing up. I didn’t feel like I needed it, my privacy was respected and once my younger brother grew up enough to understand that barging in was wrong, I never experienced anyone in my family coming in without permission.
My own house also has no locks on any of the bedroom doors, nor do I plan to put any in.