You could always give it some thought
well, I have. As you said, one is a PRIVATE space (and a curtain or cubicle door makes 0 difference on the level of privacy, it's still a public place), the other is a public space but with not much more than underwear. How long does it take to put your underwear in your cubicle anyway? You don't spend 30mn completely in the nude in there, do you?
If you are in a completely empty changing room, chances are the swimming pool will be just as empty.
The whole thing makes no sense.