Wow I didn't expect a reductio ad hitlerum in this thread.
What is the "effect of Amazon" anyway? Surely Amazon has done a lot of good. It has created jobs, it has changed how people buy things. It has also done a lot of bad. It has made it harder for small indepdendent businesses, it has engaged in anticompetitive practices. How am I supposed to "sum up" Amazon's "overall effect"?
Truthfully, I have no idea if Amazon is "good" or "bad" or "cruel" and neither does anyone else. The people making these claims confidently are posers.
Intents and motivations are irrelevant when you look at their effect (which cruelty is). Heck even the worst dictator in known history had wanted to make the world a "better place" in his own, twisted way. Some things just aren't worth their price.