Sure, but that doesn't mean that they can't be on your side. If you report that your boss is doing something which is against company policy and hurts the company, it's quite possible for HR to be simultaneously on your side and on the company's side.
They can that's was my second point when their interests can temporarily align with yours.
Or actually the actions that stem from their interests also end up benefiting you as a side-effect. Say going public with the story. Well now they are forced to protect the PR image so they will actually do something to fix the problem (move the manager to a different location), give you more money to keep quiet, etc. But they are not doing this for your they are doing it for the company's sake.
That is why a last alternative is to suggest you might go public, it forces their hand because now "cost of incident" can be rather high. As it is PR damage all across the board for the company. Of course, it might fix things in the short term but it won't be forgotten in the long term.
I don't think that an unknown Amazon employee going public could add much to the damage that the current media coverage has already inflicted. HR would probably just shrug it off. Also, taking a dispute with your employer public might cause other companies to think twice about hiring you in the future (your publicity will show up if they Google you). If you're down to your last alternative, it's probably time to find a new job.
It is hard to say. HN makes the development world pretty small. It is like a smaller provincial town where everyone kind of can find out stuff even if they don't know you personally. Damaging the image of a tech company on HN could be serious, it could impact ability to hire in the future.
But you are right, it is the nuclear option. After that even if problem is solved immediately, a stab in the back in the future is expected.
As for future employability, you are right as well. However, I can see a small start-up actually seeking out self-reliant people who have a sense of justice doing what is right. So the quality could also be appealing.
Sure, but that doesn't mean that they can't be on your side. If you report that your boss is doing something which is against company policy and hurts the company, it's quite possible for HR to be simultaneously on your side and on the company's side.