I asked the same thing about the engineering offices where I worked, and found that the reason why was because the offices didn't matter much for the people in them- we move around a lot, and the only time you're in an office is when you're figuring something out in CAD or the like. The people who work all day long in offices understandably have better furniture- we just don't need all that much.

People- interactions- matter more than places do- the happiest family I've ever met lived in a poorer neighborhood and their house was obviously not doing well.