Well, HN is something like 70% US people. So "this is for Ireland" is worth pointing out in a way that "this is for US" isn't, because US is kind of the implicit default option here.
(It's not US-only, by any means, and info about Ireland is not something we ignore because "nobody cares about that". But it's reasonable to point out that this is not data from the conditions that most people here assume by default.)
Are there any public stats on this kind of demographics?
Other than IP and the content of comments, I can't think of how would you get that data in this kind of site
Um... I've seen such a statistic cited here, but I don't remember the exact number. I tried to be conservative - I'm pretty sure it wasn't below 70%, but as I say, I don't remember precisely.
Now that you ask, I'm also not sure of the source of that statistic. I'm pretty sure dang knows, but he may not be the source of the information. It may have just been someone's informed guess, or uninformed guess for that matter.
I do know that there are lots of people not from the US here, and that you shouldn't assume, for example, that English is someone's first language. Also shouldn't assume US vs England even for native English speakers (so don't attempt to "correct" British spelling).
(It's not US-only, by any means, and info about Ireland is not something we ignore because "nobody cares about that". But it's reasonable to point out that this is not data from the conditions that most people here assume by default.)