Open offices are more vulnerable to bad cultural practices that you have no control over. A private office fixes these issues with pure physics. If open offices had librarians shushing everyone for talking too loud constantly and stopping people from shoulder surfing they would be a lot better for many people.
Managers hate these solutions because they are explicit social conflicts that creates a lot of ill will and negative morale. If a pre-commit script enforces something vs. an angry email from another engineer it's far less personal.
Worse yet, you have to be a pretty high level manager to make the middle managers do this, because some of them like the noise, or being able to get status any time, etc.
