Botanic, PlaneShift contributed to the open source world a lot, by creating a very nice open source client/server system for mmorpgs. I think the amount of man hours contributed are exceptional, and we are very proud of this contribution.
If we decide to keep closed our art or other parts of the game it's our choice, and I don't see how this is making us "bad" or "closed" or any other other nasty comments you have as usual for us.
In any case our mission is not to save the world with open source, but it's to build a game, free for players, which we enjoy creating. Like it or not, we decide what to share and how, it's our work.