The had to be a socio-economic factor with the “front parlor”, “good room”, etc. because you had to have a certain wealth to have a home large enough to leave one room mostly unused.
In my earliest days my family had the parents in one bedroom, four siblings in the other bedroom, a kitchen, and combined living/dining room. We just did not have the space to leave a part of the home unused in case “good company” dropped by. By the time we did achieve that level of wealth that practice was largely gone.