It was never even intended to be used in a scenario where you have multiple application windows. When that UI was first introduced, you could have multiple wind

It was never even intended to be used in a scenario where you have multiple application windows. When that UI was first introduced, you could have multiple windows per application, but only one application could run at a time. The behavior of having the menu bar scoped to the screen and the application not quitting when all windows were closed makes a lot of sense in that context.