I heard for the 2nd time today that a discipline is "superfluous". The guy who made this comment was a young assistant professor, who does not do research in this discipline. And, just to be fair to the commenter, that was not a serious comment, but just a casual remark.
However I think deep in his mind he believes that this discipline is "superfluous". And deep in my mind I have the same doubt from time to time. Can a discipline be superfluous? How do you know whether a discipline is worth researching or not?
PS: in this case this discipline is HCI (human computer interaction), but you could replace it with any other discipline.