Back when Amazon was registered I doubt anyone was using .us for a company website, so changing everything to point to that years after the fact would probably do more harm than good to the business, plus the fact that they at the start were only US based, so a .com at the time would have and still is the best choice for a US based brand identity.

Why would they want to break or redirect thousands (millions?) of existing links and confuse many non tech people who get redirected to a .us site?

Sure it might make us on HN feel good that .com does not equal USA and we are the center of the world, but it would make little sense otherwise.

Well, it would stop confusing the other 2 billion people on the internet that aren't in the USA.

I think the crowd here over estimates how tech savvy everyone else is, or whom actually are aware of the .us domain, and also care enough to think it should redirect there.

But we already see that non-tech-savvy people go to Amazon.com from the UK and expect to be able to buy things that they can't buy. Having a .us domain would be less confusing, for most of the people on the internet.

If you visit the amazon.com site from outside the US it should tell you you're visiting the US store and recommend you visit the local site in your country with a button that looks like your country's flag.