Suppose it must be regional. Back when I was a kid, 20 long years ago, men's rooms having a diaper station was the norm.

Even with my youngest (5), I would always use the bathroom early and check to see if they had a changing station prior to him potentially pooping himself. The majority of the time there was, but the times there wasn't was often enough to make it worth checking. Only if my wife was with us, though, otherwise it was a roll of the dice.

One time I was at a restaurant and I noted that it didn't have a changing station. Sure enough, during the meal my kid needed to be changed. I asked my wife if her restroom had a changing station, and she told me it did.

So I took my kid up to the host stand and asked to talk to the manager. I politely explained that I needed to change a diaper but there wasn't a changing station in the restroom so asked which table I could use, or if I should just use the bench in the waiting area. Manager got flustered and had a waitress check if the women's room was empty and then stood outside the door while I changed the diaper.

About a year later I happened to go back, and I did notice that the men's room had a changing table. It's a small thing, but I felt like I won one.

In northern Europe they are always in the HC bathrooms. I'v never seen one inside a gendered bathroom.