Agreed. But I am not talking about people purposefully looking under the doors or into the cracks. Sometimes though I have been in a stall with absurdly small walls or extremely large gaps around the doors, and it is more than a bit unnerving. Especially when you can clearly see people outside of your stall, then they could clearly see inside.
All I am advocating for are full walls and doors, and then ridding any of the rooms of any gender designation entirely, allowing all humans to access any toilet they so choose. Personally I am disgusted by urinals and think they should be entirely done away with anyway.
But then again, I often abdicate for things others think are crazy so there is that.