I for one prefer open plans for developers - and everyone else. A) The headphones are just a dime in the wider context. B) Sure, if you are working on the next video compression algorithm then concentration is golden and you rightly deserve a hut in the middle of endless flowerfield by the lake high in the mountains (Howl's Moving Castle style). Otherwise the ability to constantly share information with your colleagues and management (both ways) is way more important. The proverbial 9 out of 10 startups fail not because their developers could not achieve deep concentration and if you can not write JavaScript with your headphones on (on a train, while the kids watch TV, in a buzzing open plan office) maybe you lack important work skill.