Simple because it messes up the UI. You can not do this unless the UIViewControllerBasedStatusBarAppearance property in Info.plist is false. Even if it false, Apple will not resize the navBars correctly unless you rotate. So instead of dealing with customer bugs, we are simply moving them over to the new IOS7 paradigm by letting them set the property on a per window basis. To note, this does not work in PhoneNavGroup and SplitWindow. This method is deprecated and will be removed in 3.2.0