That's a sure indication that your brain was never functioning, because you made a claim, but cannot explain it, and you want me to find a reason for your assertion.
I do hope you don't behave like this in your professional capacity.
No to mention that you've descended into insults because your incapable of explaining the reasons for your decisions.
No I can explain it, I just like to see you get knotted up himmy.
The reasons are quite simple, and specific to public rest rooms.
I'm not going to explain something that's very simple to you when the answers are clear.
Why would they have cubicles that aren't full height for many many decades, especially as modern technology enables peeping toms to do much more peeping more covertly.
If it was as simple as just making full height walls and doors they would have done it by now.
One reason is for ventilation...