We have to use a more broad and nuanced perspective on the value we provide when we talk about how that value is affected by our work environment.
This sounds like "leveraging synergies". If it was possible to explain any tangible benefit to such an environment, the conversation would move forward. Really, with the Very Rare Case? Developers don't have enough work to do where they don't need to stop and talk every 10 minutes?
I think that's a questionable assumption.
If you do not even address the long-term value you provide to the company, then you can't possibly make a reasonable argument that open-offices are a detriment to that long-term value. For the record, I believe they probably are a detriment, so I have an incentive for the discourse and arguments to improve.