As much as I personally prefer isolated offices/cubes, the last 4 years in a mostly open office have definitely given me sympathy to the argument for them. I personally have noted a level of collaboration and information sharing that just didn't happen in the more isolated environments. There is something pragmatically useful about having people be able to jump in with their feedback or expertise.
The more isolated people are the more you have to go out of your way to ensure information dissemination and feedback channels are available and utilized. It certainly can work, but I haven't seen it work as well.
Open rooms promote teaching, spontaneous design discussions, etc, that just doesn't happen in the same way over e-mail, chat, stand-up meetings, etc.
There are arguments to go both ways. I used to hate open offices, now I'm sympathetic to them.
A key to making the open office tolerable is that it should not mean no isolation. There are ways to address their concerns. eg, headphones are essential. Obscuring line of site is very helpful. My current situation has me in an area of "open rooms", where rooms with ~11 desks are arraigned in an open office-esque fashion. It's pretty decent. Not super-open, but people can "share space" with the people relevant to them.