Have had some where the shower is just glass panels for the room to see (and no, it wasn't that kind of hotel).

Another hotel in a small town here in Germany where it had shutter-style doors and where the roof of the bathroom didn't go all the way to the actual ceiling, so you can hear everything.

Both in the name of aesthetic, clearly.

I stayed at one in Iceland where the entire bathroom wall facing the living room was unfrosted glass, including the door. The living room was open concept so it was hard to avoid seeing into the bathroom. Great place for couples to bring their entire selves to the relationship.