The research[1] that various journalists in Washington Post, Harvard Business Review, WSJ, etc are pointing to is a survey of employees' satisfaction levels and not an analysis comparing business results.
If that oft-cited survey is the best ammunition we have, it won't move the needle towards private offices. What we need is business evidence of private offices enabling productivity levels superior to everyone else with open offices.
[1] http://www.sciencedirect.com/science/article/pii/S0272494413...
E.g.: http://www.ics.uci.edu/~gmark/CHI2005.pdf
Or:
"In 80 clinical trials, Dr. Glenn Wilson, a psychiatrist at King's College London University, monitored the IQ of workers throughout the day. He found the IQ of those who tried to juggle messages and work fell by 10 points -- the equivalent to missing a whole night's sleep and more than double the 4-point fall seen after smoking marijuana. "This is a very real and widespread phenomenon," Wilson said. "We have found that this obsession with looking at messages, if unchecked, will damage a worker's performance by reducing their mental sharpness."
You are disagreeing with people who may not actually disagree with you (I know I think open concept offices are terrible for most purposes).
Then the comment I was replying to missed TFA, because it gives pointers to research on the issue.