Blind or vision impaired users can employ GUIs which have been adapted for them by the use of a combination of tactile and sonic devices and software. In that case the word "graphic" seems patently absurd.
Computer scientists doing research on future user interfaces often put as much or even more stress on tactile control and feedback or sonic control and feedback than on the visual feedback given by most GUIs. In these cases the term "graphical user interface" seems inadequate.
Given the recent spread of touchscreens at the beginning of this millennium, and the presence of massive sonic feedback, and even tactile response (joystick feedback actuators) in more and more game platforms and games software, the acronym GUI might seem lacking, in these particular instances.
People will probably go on using the term GUI, regardless of its disconnection with a changing reality. The usefulness of the term "direct manipulation interface" lies in its capacity to remind practitioners (or anyone interested in discussing the user interface) that there is more to the GUI than meets the eye, and to serve as a pointer towards fundamental analysis of the practical essence of the GUI.