If you spend any time reading their retail forums [1], you'll see almost everyone lambasting Amazon constantly. Either disgruntled sellers who broke the rules and got terminated, or normal, hardworking mom-and-pop stores that were all but forced to sell on Amazon and consistently lose money due to amazon's ever-changing policies, poor support, and catering to large retailers. Large retailers get a direct line and quality support, while most sellers on Amazon get treated like crap.
[1]: https://sellercentral.amazon.com/forums/