Besides, it's pretty much the central tenet of this argument. The "idea guy" has a grand vision and it's left to the artists, programmers, etc to get on with the boring and menial task of turning the Best Game Idea Ever into a reality.
I said it is necessary, didn't I? All I implied was that it's not the most important thing for an artist.
It was just a metaphor and I never claimed it was entirely accurate, it talks more about their artistic contribution to the game than the amount of work they put in. They could very well be considered artist and their lines of code or drawings could be art in their own right, but ideally, they don't change what the game is in a significant way. Unless of course they are better game designers than the game designer.
Why does everyone here always focus on monetary value by the way?