"For me this was easily solved by explaining that it is a lot easier to drop me a line by email or chat and I'd get back to them as soon as I was available."
Easier? For them? Or you? A perennial argument for open floor plans is that it 'fosters open dialogue' and other such twaddle. For someone to be standing 6 feet from you and be told it'd "easier" to go back to their desk and send you an email instead of just talking to you is ... counter-intuitive at the very least. Unbelievable to some.
I was in an 'open floor plan' a few years back, and would email over to the sysadmin who sat 8 feet from me. The owner yelled at us (and by extension, the other 8 people in the open area, distracting all of them) because we weren't talking directly. "That's why you're all out here - to communicate better!" And then he stormed back to his private office.
"I've always worked this way, focusing on something while a part of me was processing what was said around and being able to "pause" what I was doing to help around and get back to my work pretty easily. Of course it does not work all the time and some times you just need to focus for a few hours and in this case I just increase the volume of my music in my headphones and stop caring about the rest."
If this is actually the case, you're in the minority. After doing this for... 19(?) years, few developers I've met or worked with are actually more productive in open environments. A fair number are more comfortable, but they've not been any more productive (and in some cases, less so) than anyone else on the team, nor have they ever been markedly more productive than people with more private surroundings. My metric for this is purely subjective reading of the quality of their work - number/severity of bugs, features worked on, complexity of code/project/features/bugs/etc. Yeah, so and so was great to work with, pleasant, fun, etc, but always was the last to get things done, always had a few lingering bugs to clean up, never took on the harder features/bugs, etc. Again, totally subjective reading on my part, and it might be biased some because I'm generally not in favor of open floor plans.
I'm in favor of private work spaces and open common areas where people can meet to collaborate when they want. I understand it's an extra expense, and there are times when it's simply not possible. The best teams I've seen operate were ones where it was s small team with private offices and available open areas for collaborative meetings. Tables/desks there allowed for bringing laptops to work on code when needed for longer periods as a small group. Usually a group of 2-4 would brainstorm an issue in the open area, possibly hack out a few things on laptops, people would generally go back to private offices for a while to hammer things out, then come back to discuss and demo. I saw this most recently as an outside contractor coming in to a local company, and they were one of the best teams I'd ever worked with. Things got done rather quickly, everyone had a good sense of responsibility, etc (this was ... 4 people, then 5, IIRC). But then things changed, a couple more people came on, physical environment changed, and things went downhill. I can't say it was entirely the change in physical space, but personally I think it contributed a lot - more people were in open spaces, more 'collaboration' was someone standing near someone's desk trying to do that there (the open area and large meeting rooms were rarely available due to company expansion). Things took longer to get done, and there were more lingering bugs that took longer to sort out.
Yes, 100% anecdotal, but I watched this myself as a partial outsider. I had no long term vested interest, and was only onsite part time - the open vs closed stuff didn't actually affect me - I always did my work at home.