In terms of the panel passing steampunk but not cybergoth... Makes no sense to me. cybergoth is bigger in Japan than steampunk (correct me if I'm wrong... I'm quite sure), therefore I'd say it belonged more. :/
In terms of just people wearing steampunk stuff around... I don't see why there's any problem with it. A wise cosplayer (whose username I have forgotten XD) once said: "When you start funding my costuming endeavors, then you can tell me what to wear."