Philosophy is a difficult and ancient subject which deserves some time spent on analyzing what it is we are trying to actually say. Then we are free to argue either the definition of the term they are using or their application of that definition to the argument. I suppose what I am really driving at is the methodology of argumentation. Even in philosophy classes you get a ton of people who don't know how to make the moves. What I think he was getting at was that doing philosophy is a mixture of getting clear on the arguments and then progressing to new material and ways of understanding things.
Most professors are very clear on the arguments but fail when it comes to making new moves.
None of us plan on changing the landscape of philosophy, but we should be knowledgeable of the relevant material and not afraid to reference arguments in the literature. By grounding our arguments in the relevant material we avoid a lot of pitfalls that tend to occur when trying to invent the wheel. When suggesting material for discussion include a small bibliography of material that others can read to get up to speed on the literature. Also, take some responsibility on trying to get clear on the arguments, because only then can we actually start to make progress rather than arguing the same points over and over again. Trust me, this is as much of a call for responsibility on myself as well as from others.