Because we're afraid of making spaces too small, we often go to the opposite extreme and make them too big for comfort. The ceiling height in the TV alcove (to the right of the post) is just 6 ft. 10-1/2 in. -- too low by most accounts -- yet it's the coziest spot in the home. It looks out into the larger spaces that surround it, so it doesn't feel small at all.
If people really considered the cost of a vaulted ceiling, I'm convinced they would invest their money a different way. The trouble is that it's easy to say "12-ft.-high ceiling" and have someone understand what you mean. It's much harder to communicate a desire for beautiful proportions and comfortable nooks. These things are less tangible and therefore less commonly implemented. Once we have a language for them, I suspect that many more people will choose to spend their money on these life-enhancing qualities rather than on tallness.
Most people think they should be able to tell from a floor plan what a house will look and feel like. But in fact a floor plan tells almost nothing about the "feel" of a house. It's like looking at a map of a city and assuming that it will tell you what it is like to be there. The map represents only two dimensions, while the experience of being in a place resides in three dimensions -- in the canopy of the trees, the height of the buildings, the skyways that bridge overhead -- everything the map can't show. The only thing a map can tell you is how to direct your feet from one place to another. It's the same with floor plans. The "feel" comes from the experience of our senses, not just from the route we take from one room to the next.