Could, maybe, working over a VNC connection or on a remote X terminal be a good reason?
VNC connections are very, very common for remote administrative assitance and remote X terminals are what largest school deployments use to allow dozens of students to connect to one powerful X terminal server.
If GNOME Shell becomes unusable over a remote X of VNC connection, then it will be of a very limited use and likely fail as a generic replacement for Gnome panel.