I have to agree with JeremyG in that there should be two ratings (personal taste and technical quality). Otherwise, work that comes from a know artist that consistently produces quality work may receive a "1" from someone for numerous reasons: personal taste, completeness, expectations, composition, etc.
As an example, I would be less inclined to give a higher rating to work from a seasoned artist, if the new work didn't move in new directions or somehow improve in quality and completeness from previous works, or didn't support the most cutting edge of skinning, than I would of a similar quality work from a less experienced or "greener" artist. Seasoned artists should be challenged to excel and stay fresh and most do "push the envelope" vs. cranking out S.O.S. By the same token, a newer artist does need encouragement to continue, if there is merit in their work, for they may become the next "great" artist. Shooting them down would just deprive the community the diversity it needs to grow and increase membership. Also if I would not personally use a piece of work because of my "taste", I would be more inclined to rate that piece lower than an item that I would use.
I would finally add that ratings need to be tied to comments. Someone should not be allowed to post any sort of rating without providing valid commentary to support their ratings. Valid commentary not only assists the artist in improving the quality of their work, but educates users as to what "the community" perceives as solid quality work and what is not. "Sucks", "Way Cool",

,etc. are not valid commentary.
I appreciate Frogboy bringing this issue to our attention, but if the Admins of WinCustomize wish to truly provide quality work and knowledge of quality work to community as a whole and constructive feedback to artists, the rating system needs to be overhauled.