Nah, adding an interior wall during construction is cheap. They build open floorplans because that's what people want. I've been on dozens of custom house builds and ALL of them had open floorplans. Whether or not they're good is up for debate, though!
I see the appeal of both but lean anti-open floorplan. Like I want walls in a kitchen but prefer when it opens up to the living room or dining room. I currently have an "enclosed" kitchen and I don't like that it feels separate
