I think the toilet wall thing is because we have an expectation that every public building must have public toilets available. Places don’t want you to fuck or shoot up in the bathrooms, so they make them un-private so you hurry the hell up and leave. It’s a bit of hostile architecture, like making park benches that you can’t lie down on to keep people from trying to sleep on them. Make the “undesirables” uncomfortable enough and maybe they’ll go be undesirable somewhere else. Meanwhile it’s just a little bit less nice for everyone else as well.