I actually find the metaphor quite useful–as a developer I can develop a GUI application utilizing a common menu metaphor but _not_ always have a window open; essentially an application is a 'toolbox', presenting its tools via the global menu, and documents/'work' appear as windows. For context, I used Windows all my life before switching to Mac about six years ago, and I find this makes a lot more sense than one menu per window, where application developers often like to go their own way and implement their own menu metaphors.