Comment 9 for bug 998911

The problem is that the software stack that makes up Unity is designed to work together as a system. If you start removing a part of the system, it turns out the system no longer works as expected. Removing the desktop portion of the desktop shell means that input and action on the desktop does not get to the shell.

That said, there may be some underlying change that can accommodate this pathology. Marking as low priority for someone to review as time permits.