I am making a case we should not call these environments "operating systems", they are more like "shells". Because the integration of applications (common API)

I am making a case we should not call these environments "operating systems", they are more like "shells". Because the integration of applications (common API) in the OS happens towards the hardware, while here, it happens towards the user. So it's different from an OS, and ideally, you should be able to mix and match the environment and the OS as you wish (as you do, you said you run on a "guest" OS). Then we wouldn't care so much whether the applications are on the desktop or in the cloud.