Which do you prefer? The modern condo with an open floor plan and cathedral ceilings? Or the pre-war rambling house with multiple rooms with doors, nooks and crannies. If you are sharing housing with unrelated people, you should prefer the latter.
These spaces allow individuals to have privacy even when others are home. Think about it – your housemate has a friend over and they are visiting in the living room. You have a friend over and you are making tea in the kitchen. In a house with doors you can close the doors and each of you have your own visit with your friend. In an open space – well the likelihood is that either the four of you visit together or one pair goes out or you simply don’t have friends visit you at home.
Older houses were built for bigger families. Maybe intuitively they understood the value of separate spaces?