That had been proposed through a mockup (by andyrock IIRC) some months ago.
The problem is that is hard to manage the resized windows that have menu-bars longer than their own size.
Grouping the menus could be a solution, but it's quite hard to do in the current state (also for global menu).
Also, this would make moving a window (dragging it from its top bar) harder.
I think we need some more input from designers on this point.
That had been proposed through a mockup (by andyrock IIRC) some months ago.
The problem is that is hard to manage the resized windows that have menu-bars longer than their own size.
Grouping the menus could be a solution, but it's quite hard to do in the current state (also for global menu).
Also, this would make moving a window (dragging it from its top bar) harder.
I think we need some more input from designers on this point.