[mrweasel]

It's extremely cheap to built and operate. Cleaning one large office is fast and hence cheaper, than 10 smaller offices.

Often the "lost productivity" isn't factored into the cost of open plan offices, mostly because it's to complex I think. Interestingly the gain from better communication is always factored in as a positive.

I do know people that prefer open plan offices. They all have headphone on for a large part of the day though. People that prefer an eerie silence, like myself, aren't normally not considered when planning office building.

[blacksmythe]

  >> It's extremely cheap to built and operate. 

The cost of the facility is inconsequential compared to the efficiency of the developers working there.