Earlier quoted context omitted.
The investments they've done for something that is their resposibility in the first place. If I go to a restaurant and the food is rancid, I wouldn't be appeased when the owner tells me "we've made investments to stop the food from going bad, we even bought a refrigerator!".
The analogy is not valid. The marketplace at Amazon makes it a (large scale) mall, or a food court for your analogy, not the shop that is selling. If the food from a restaurant at a mall comes out bad, would you blame the restaurant, or the mall?
The fact that Amazon displays the product—including choosing which description from different sources to use when there are multiple sources of the same product—charges my credit card, handles returns, etc., makes it more like a shop than a mall or food court. It's a consignment shop that has to pay the person who made the product available for sale once it sells, when that person is not Amazon itself, but it's still a shop. It's not like a mall or food court that provides a venue through which I gain access to directly interact with individual vendors.