Partially related: Is anyone else bothered by the volume of negative reviews on Amazon that simply target an individual seller rather than the product? All in

Partially related: Is anyone else bothered by the volume of negative reviews on Amazon that simply target an individual seller rather than the product? All instances of any product are covered by the same set of reviews, regardless who the seller was, so reviews like this are totally unfair in dragging the product's rating down. Why doesn't Amazon have a policy against this?