Let\'s look at it starting from a different perspective. We know that intellectual property slows progress, as even the GNU GPL that Planeshift has says. If something is fundamentally wrong, then logically it must also be practically wrong. When copyrights were the only way software worked, nobody believed that public domain-style software would ever work, because they didn\'t see the incentive. Linux proved that it\'s truly better to be fundamentally right, and even Red Hat made a lot of money on it. Even the giant Microsoft is tumbling.
Sekhmet is surely right that many portions are practically identical from one game to another. Try the texture of a brick, or the shape of a sword, for example. I could claim that PS doesn\'t have its own look and feel, because the other CS based games feel the same.
Movies do the same thing. They just shuffle actors around and change their clothes. \"I don\'t wanna see T3, \'cause they just used the actor from Hercules in New York and changed his clothes.\"
Game developers that want to be original simply don\'t copy stuff unless they can satisfactorily change it to something new. And those who don\'t change the graphics simply don\'t want to. That\'s flattery. :]
On the other hand, Planeshift does make a good point about artists refusing to submit their work as GPL. There is a solution, though. PS can keep all the contracts and licenses the same, but piece by piece, they can accept public domain replacements, now that they have popularity on their side. I would donate public domain art if I could draw better than a 5 year old child drawing with his left foot.
On a related note, yes, Planeshift can be a profitable GPL product by operating advertisement-driven \"value-added servers\".