My theory is that the people in power (management) quickly get to the level where everything they do in their jobs requires talking to multiple people and coordinating and they apply that need to everybody's work so they think all work is about "Collaboration" and "Connecting".
At least for engineering I think there is not that much need for constant collaboration but there is a big need for focused work which is hard to do in an open office.
In addition open offices even fail for collaboration. I work in a cube farm with some open office space and I rarely see people actually collaborate there. Instead people have headsets and are desperately trying to focus. I used to work in team rooms before and there we talked to each other a lot in comparison.