We just bought a house, it was recently renovated and basically all of the walls in the kitchen/dining/living rooms were removed, and it sat on the market for a long time compared to similarly priced houses in the area. Based on location and everything else, the only thing we could conclude was that people don't like open floor plans as much as HGTV would lead us to believe, but it's awesome for us.
Our major complaint about every apartment we've ever lived in is that half the square footage is hidden in bedrooms no one ever spends time in. We have small children, and apartment buildings were generally quite reluctant to rent us less space than they thought we needed, but we generally chose apartments based on how big the living/kitchen area was. Given the choice between a 1,500 sq ft 2 bedroom with a 1,200 sq ft living room, and a 2,000 sq ft 4 bedroom with a 600 sq ft living room, we'll take the 2 bedroom all day, because we spend all of our time in the main space together, and we only sleep in the bedrooms. Having open space where we can all be together is massively important to our quality of life. (Naturally this will probably change as the kids get older...)
Somewhat related, when I was growing up, all of the families in our friend group tended to congregate at one family's house. They had the biggest house by far, but what I find funny in retrospect is that everyone's homes were laid out the same way, but the big house was SO much bigger, that even the compartmentalized rooms ended up feeling like an open floor plan.
People seem to subconsciously want a kitchen and a dining room and a sitting room and a living room like Downton Abbey, but they don't notice that each room in Downton Abbey is the size of a small gymnasium. At least from my perspective, it's better to have one room like that, than to try and cram all of the other rooms into a too small space.
Reading back over this, I realize I sound very opinionated, and I suppose that's because I am! Sometimes I go into a house and I just can't believe how someone could make a whole 2,000 sq ft feel so small and cramped.