I think the HN audience is more diverse than people think. The average HNer is not in Silicon Valley for instance.
Microsoft, Google, Nintendo, Facebook, F5 and other local firms don't quite have the Hired to Fired pipeline that occurs within 12 to 24 months for the average Amazonian. At each stage it seems Amazon is lighting money on fire...
The people I've mentioned above who seem happy at AMZN have the common denominator that the AMZN job was a definite step up from what they were doing before.
Ironically, on the other hand, when I was first leaving the Army 15 years ago, the enlisted guys leaving at the same time were overwhelmingly all looking to work either as roughnecks or in Amazon distribution centers because they paid so much better than anything else you could expect to get hired for with no qualifications other than willingness to get beat up and tired.