I totally take your point (yes, the 2nd image is 'better' for the most part), and it's one I considered when I wrote my comment. I think it's interesting to compare it with OSX and its global menubar.

I'd like to see a windowing system that totally revamps how we think about screens, apps, windows, tabs; menus, toolbars, etc. When should a menu be linked to an app and when should it be linked to a tab? How can we meaningfully manage all these things together? Do we really need a 5th level in this hierarchy? Is it really a hierarchy, or should an 'app' be able to overlap more than one screen? Does it ever make sense for a tab (image a 'naked' pane displaying an image) to be available to more than one app? etc.

I feel like, yes, we need to solve these issues at a higher-than-app level, because every app doing its own thing will just be incredibly confusing.