Open plan offices are another bad idea dishonestly sold to tech workers. They aren't more "collaborative". The low-level anxiety and misanthropy that they foster is being informally called "open plan syndrome" by psychiatrists in the Bay Area. People collaborate less in open-plan offices and, while some think their purpose is to intimidate people into working, people actually fuck around way more.
I actually don't think the purpose of open-plan offices is intimidation, nor that they are cheap. It's marketing. "Startup" is now a brand. At high levels, it's an excuse for bad behavior. ("We can't afford the severance cost or publicity of a layoff, so we'll fire 10 percent for phony 'performance' reasons. They knew this was a risk when they joined a startup.") For the rest, it's a useful ruse that allows companies that are even more cutthroat (just as young gangsters are typically more violent than older criminals who recognize that bloodshed is bad for business) to somehow present themselves as Not Corporate. And let's be honest: open-plan offices look sleek, busy, and vibrant. They're photogenic. They're also awful places to work, just as Times Square is (to New Yorkers, anyway) an undesirable place to live.
Open-plan offices also raise interesting questions about legality and discrimination. There's a solid argument that they discriminate unfairly against older workers, people with disabilities, and women. I certainly wouldn't go into anywhere typical tech office if I were pregnant; I can handle the open-plan stress with enough meds, but can the baby? The nagging but chronic stress of being visible from behind can't be good for the fetus. So what should the legal status of open-plan offices be? Obviously, they shouldn't be banned outright. Trading floors need them, and companies under 20 people should be allowed to use whatever office space makes sense for them. Ultimately, though, while I think open-plan work environments should be legal, I think the burden of proof out to lie with the employer, and "we're a tech company" is not sufficient. I also think that companies using open-plan offices should be taxed to pay for a public disability fund in order to compensate for the health costs that companies can currently get away with externalizing.