Amazon calculates a product's star ratings based on a machine learned model instead of a raw data average. The model takes into account factors including the age of a rating, whether the ratings are from verified purchasers and factors that establish reviewer trustworthiness.
A book filled with fabricated and false stories without any mention of whether the stories and authentic or not. Just because it is from Darussalam it doesn't mean its authentic. All readers who read stories in it pls confirm it with the authenticity checks made by the scholars which are available in Arabic .