I wouldn't blame the consumer on this. Retailers are responsible for the things they sell. That includes if it's low quality or if it says it's something that it isn't (counterfeit etc).
Also hosting fake reviews etc is also something they are responsible for.
Is it a veil? Imagine you are a landlord and you rent to a Walmart. Are you as the landlord responsible for all of Walmart's products? It is the same thing but Amazon owns a virtual high traveled location instead of the landlord who owns a place on a busy street. Amazon shouldn't be responsible for the third party seller, but it should be extremely clear that it is a third party seller, like the sign on the side of a building.
