I think in essence Amazon is a VC funded charity. Amazon has been great for consumers, driving down the cost of all sorts of products. For their VC backers, the returns have been less than stellar Amazon's model is to be the low margin competitor in each segment, ostensibly to drive out competition in the hopes of raising margins later. This doesn't seem to be happening as other competitors are matching or bettering their prices.
The washup being that Amazon will continue to exist, continuing to make minimal profits (especially in comparison to their VC backer's investments). Hence my view that their VC backers are essentially making low interest loans/donations to a charity whose purpose is to deliver lower prices to consumers.