Amazon basically became a rigged marketplace where those who thrive are the ones who can get away with a lot of things. From completely disregarding guidelines, TOS, targeted attacks to destroy competitors listings, you name it.
It's just like prisons, people go in and come out worst because that's the game that has to be played in order to survive.
The only one to blame is Amazon that promoted these practices by giving leverage to those who did it. With more revenue, more exposure, privileged access to Amazon account managers (yes, talking to a human is a privilege for an Amazon Seller).