We're presumably speaking about a shared bathroom in your home, not about travel accommodation. It would infringe upon a fundamental need for privacy that people have: having a space that is yours alone, where you are free to do whatever, without being observed by others.
I've seen some (studio) apartments that have a private bathroom that outside the front door, but still inside the building. I would very much dislike this: to me, it feels like it would break my private space, forcing me to allow for the possibility to run into others each time I go to the bathroom.
I lived in a dorm for 2 years in college. Not only did I not have a private bathroom, but I also had a roommate, so really I had no reliably private place at all. It was fine. I mean occasionally privacy would be nice, but I also enjoyed the increased sense of community in the dorms.
Maybe you'd hate this, but that doesn't make it a violation of human rights or anything.
Of course it's not for travel, I understand that. But neither are dorms. And people stay in youth hostels and similar accommodations for longer periods too.
> upon a fundamental need for privacy that people have
I don't think you should project your personal preferences with objective needs. Besides, you share bathrooms at the office where you spend 8 hours a day, are you also concerned about running into people there?
I've seen some (studio) apartments that have a private bathroom that outside the front door, but still inside the building. I would very much dislike this: to me, it feels like it would break my private space, forcing me to allow for the possibility to run into others each time I go to the bathroom.