I wonder - does anyone actually believe that anymore? I've always found that to be more the rationalization people use since it sounds good. I've generally found the actual reasons to be more of an attempt to remind employees of hierarchy (make sure the individual contributors know their place), control (much easier to monitor people than if there were actual offices) and cost (giving workers a little table space allows you to pack in 2 or 3 times as many).

Where I am, while the workers dislike the open space for obvious reasons, the managers who have actual offices now seem happier, so I guess that is something.