I have often wondered about this. I think that the main reason that Linux does not have GUI DC clients, and many other programs for that matter, is that cmd line rules in Linux. In addition, many of the users for DC are Windows users. Perhaps the need was never there, or the effort to develop a GUI client was never justified (not enough users?).
When I was running the Linux cmd line for classic seti, I too sometimes wished that there was some form of GUI. All I could do was run in verbose mode to see the real time progress. There are not any native GUI clients for DC projects that I know of, although you may be able to find a third party application to do this(?). Hopefully some of the Linux gurus will have more to say?