For the people who do prefer them (and also spend most of their time writing code), I would be curious to know the following:
(1) How many years have you spent, total, working as a developer in an office environment every day?
(2) What percentage of those years were in open office layouts vs. sharing an office vs. having a private office?
(3) How many times a day, on average, do you interrupt other people with questions, vs. other people interrupting you?
I bring this up because I just really truly don't get the occasional open office boosterism here. My current theory is that most of it comes from people who are still in the honeymoon phase of their career (like, the first few years after college when everything about the workplace still has some novelty to it).
I say this because it seems like many/most of the people I talk to in person who like the open office idea have either literally never had a private office, or are relatively fresh out of college and get a job at Google (or a startup, or wherever), and they're still so excited about everything that even the things that are hassles (like open office plans?) seem like they're brimming with novelty.
Alternately, a lot of the people I talk to who like open offices tend to be those that are constantly pinging the people around them for help, but people rarely or never ping them for help. The only people I've known at my current company who want open offices (or even officemates) are these kinds of people. They don't even realize that they have an 'interruption deficit' (for lack of a better term) within their team, they just like the idea of everyone being more readily available to them and they don't pay the price for it since they rarely get interrupted themselves.