There was a post somewhere that I saw some time ago and there was a bathroom a lot like this, not all glass, but a glass window you could see to and from the bed, as well as mirrors all over that let you see to and from the bed and someone explained that those kinds of bathrooms/hotel rooms are that way for sex stuff, like paid sex stuff. I don't remember the exact reasoning, but it's not to watch someone take a dump. I mean I guess if someone's into that then two birds with one stone, but it was more along the lines of security or something, so you can see neither party is doing something malicious, stealing or spicing a drink with something.
Maybe the shower will fog up with a switch? Not that i never seen a hotel room with shower like this, but it's mostly those cheap budget hotel and it has frosted glass, not clear like this.
I stayed at a pretty upscale hotel in Singapore that had a see-through shower like this. Fortunately the toilet was separate and had a proper door. I think it’s primarily meant for couples. Definitely bad if you’re traveling with family.