They don’t suck to live in. I would much rather live in an open floor plan. Maybe your needs are different and you need privacy within the common areas of your house, but not everyone has those same needs.
Our house has an open kitchen + living room + entryway + stairway, and that's not so bad—because we also have a huge basement, four bedrooms for 2 adults + 3 kids, two extra rooms that are walled off with doors (we had to add the doors, though...), et c. So that open space is OK, because we have way more house than we'd need to be similarly-comfortable if it were better laid out, including having more walls and doors.
We have an open floor plan in our main living area. It's a "give" in that I am able to watch my children playing in the common area from the kitchen. It's a "take" in that if I am cooking with the exhaust fan on, there's no way you can hear the TV.
It's also a take in the sense that when people come over, they see the mess in the kitchen if there is one. Sometimes a door is nice that way.