This doesn't make sense to me as it has the opposite effect. If I want to buy an item, I'm pretty dead set on buying it. Now it's just to figure out which company's to buy. If I can't rely on reviews and get a terrible unit, I will return it and no longer trust Amazon for that item and turn elsewhere. Ultimately, Amazon lost some money, I lost some time, and Amazon lost the sale.
Reviews will eventually have to rely on non-store, external sites.