> IIUC applications can set their window title or argv[0] to anything they want and I don't think that's a feature that would likely be dropped making the point moot.
And in a secure environement with server side decoration, this application's provided tittle can either be ignored or be added in addition to a color or text which provide the server's view of the application.
That said, one could have virtual desktop/environment which would group application by security level even with client side decoration, of course for single applications this is annoying..