Example:
Run unity on a dual-head setup.
Have an program maximised on both screens.
Now when you click on one program to give it focus, the other program on the other screen will loose focus.
This other program that has lost focus no longer has it's close/minimize/unmaximize buttons visible or the title bar text.
This is broken:
* The blank toolbar becomes wasted space.
* It's unintuitive to show the titlebar - clicking the blank title bar for the out of focus but maximized app does nothing - you have to click on the main app window first to make the menu bar appear.
* It stops the title-bar functionality being one click, which it should be.
* It's possible that the titlebar on the out-of-focus window on the other screen says something useful that you can't see without focusing it.
Reproduced the incorrect behavior on Precise.
Suggest setting the importance to High.