My personal opinion, stated many times over the last few years, is that rating should be made public, ideally linked to comments and downloads. That way someone would have to download a skin and comment to rate it.
There's nothing wrong with giving a low rating to something you don't like - just say why! Same for a high rating.
Drive-by raters will not be given any sympathy and will be dealt with accordingly.
Finally, like most people here, I'm getting sick of hearing about ratings. I just wish the moaning minnies would find something else to whinge about. There's hardly a week goes by without an outburst - enough already, shut-up and skin something.