The analogy that a screenshot is a personal photograph of someone else's art seems to be the most appropriate. It does seem at least reasonable to think that since WC is so big and has such large traffic that the "someone else" might want some control over what they consider to be their art.
Since it is the screenshot section that generates this controversy, I have a suggestion on how both sides of this *debate* could be placated. Why not make the screenshot section only connected to the personal WC pages? In other words, the WC wide library of screenshots goes away, but the ability to upload screenshots does not - at least for those who have setup (and who can setup) personal WC pages. The uploaded screenshots would still be subject to moderation, still available to the public, but not in that way that someone just stumbles upon the particular screenshot. The amount of available space for upload could be determined by WC rank, subscription level or other.
Three things would be afforded by doing this: (1) artists - and the artists representative - can't really object to the screenshots (at least not in the sense of objecting to WC policy), (2) WC is provided some protection - of the legal variety - from copyright infringement claims, and (3) screenshot *spammers* are kept in check.
Just my idea, comments welcomed!