I'm always stymied when a juried exhibit asks for my artist statment along with my submissions. My first reactiion is, "Oh no, not that again!" and my second reaction is, "Do I want to get into that exhibit so much that I'll put myself through this again?" I've written artist statements in the past. I hate doing them and I don't understand why they are needed.
David Saxe explores this issue much more articulately than I can. He has a short article posted on the Black Star Rising website titled Why I Don't Like Artist Statements.
As he says, the pictures should speak for themselves. They are, after all, an expression of the artist's vision. Their merit is measured by their ability to give voice to what the artist is saying. If it's not so clear, maybe the artist needs to work on being more articulate through the chosen medium.
Saxe concedes he still submits artist statements when he has no alternative. If he doesn't fight the system, why should I?