[alkonaut]

> If open-offices are so remarkably detrimental,

Assume they aren't. This place may of course be a bit biased - but among developers the opinion is at least appears to be very clear on that open offices suck. I'd even dare argue that many developers would either not work at a company with open offices, or would at least factor it in and weigh it against compensation.

Now if this is the case, then regardless of whether there are tangible benefits of having private offices, companies would either lose out on talent, or need to compensate them more than they otherwise would. See the point isn't only whether developers are less happy or less productive in open offices - the point is also whether they believe they are less happy and less productive in open offices. And that is much easier to test/prove than whether they actually are.