People usually use their phones in portrait mode. People often taking vertical photos and videos. People read books, and every book has portrait pages. Almost every website has unused space on left and right.
But when people see my vertical monitors they all like: oh man, you are weirdo, that's awful and uncomfortable.

Hahahaha I have this problem at work. I have 3 vertical monitors, so I get a lot of comments about it. Usually saying that I can check emails faster, read PDFs or view more code at once gets them to go away.

@Schroedinbug I have only 2 (laptop can't handle third one). Usually saying "Fuck you" to them helps

@rostopira Hahahaha That would do it too.

I'm using a laptop as well, but on a dock. I have to disable the main screen to do it, but you might be able to get it to work by using an adapter if you don't have 3 of the same input. I'm doing two DVI and a VGA.

@Schroedinbug I have one type-c, dock has 4 ports (2хDP, HDMI, VGA), but doesn't support 3 monitors. Maybe I will get new dock someday 🤔

People who make vertical photos should be treated like the puppies I mentioned a few days ago in one of my comments. Unless its a photo of the eiffeltower or tower of pisa or something like that. (although I wonder why someone would make those pictures, since there are free photos online of the same thing in a way better quality then you can ever make).