Superficially things are posted about America, but usually that's more a problem with the site that's linked to being written for an American audience - the majority of articles that make it to the front page are about things that have global impact. Actual content within HN is pretty much entirely for a global audience - Show HN is usually about startups/projects with global reach. Ask HN is usually about things that affect an individual. Hiring threads are very often for remote jobs where people can work anywhere.
Example: "2 years are now a long support cycle for phones as most people get carrier upgrades every 2 years anyway" (from the Android Browser vuln thread.
This is only valid in the US because most people in Europe, Africa, Asia, India, etc. buy their phones seperate from their contract, so there is no "automatic" upgrade.
Another example was in the Popcorn-Time threads the "Who needs this if you have Netflix?" – Netflix doesn't even exist in most countries, and where it does exist, they only have like a dozen series, nowhere near the US version, so it provides no benefit. Hell, here where I live even DVD rental is still used, even Amazon provides DVD rental here.
Most of the people in the comments assume that everyone is in the US and a Hacker-News without that would be great.
The fact that you're using PopcornTime as an example is interesting - there hasn't been a Popcorntime discussion on HN for months. There's been plenty of threads[1], but mostly about the development of the apps. You have to go back 5 months for real discussion (more than 100 comments). I realise that this is just one example, but I'd be wary of suggesting there's an implicit bias to US-centric discussion using a thread from that long ago on a forum that gets hundreds of submissions and dozens of discussions daily.
Essentially, I think it's important to question how much of the US focus is real and how much stems from our biases. I don't think there's very much, but maybe that's because I ignore it.
Superficially things are posted about America, but usually that's more a problem with the site that's linked to being written for an American audience - the majority of articles that make it to the front page are about things that have global impact. Actual content within HN is pretty much entirely for a global audience - Show HN is usually about startups/projects with global reach. Ask HN is usually about things that affect an individual. Hiring threads are very often for remote jobs where people can work anywhere.