Difference between citizenry and ethnicity.

On Reddit and elsewhere, you can see lots of Irish people (in Ireland) saying that Irish-Americans aren't actually Irish and shouldn't say they are. One Redditor said that you can't call yourself Irish unless you live there and have a Irish passport.

What an odd thing. Surely, these folks must be aware that there's a distinction between citizenry and ethnicity, and obviously soi-dissant Irish-Americans do not think they are Irish citizens?

At any rate, I will be willing to take the "You're not really Irish!" thing seriously from Irish nationals just as soon as I hear them tell Chinese-Americans they aren't Chinese, Korean-Americans they aren't Korean, Arab-Americans they aren't Arab, etc.