> Does it really bother you that people care about their heritage?

I'm making an observation. It's not a unique observation. People in countries of ancestry find it ridiculous when Americans far removed from their culture visit and claim to be "one of them", or worse, like a member of "the family". I'm sure you don't enjoy people who make fraudulent claims about themselves either, especially when it is an attempt to establish a false camaraderie with you.

I think the mid-century pressure to assimilate into corporate American culture, along with all the tactics used by the state to disrupt ethnic neighborhoods and communities like scattering them across newly-created suburbs to hasten assimilation, left people disoriented, traumatized, and feeling culturally homeless. There's a nostalgia for the ethnic neighborhood that was lost (in the case of Italian neighborhoods, you can see it reflected in movies like "The Godfather"). Assimilation - and synthesis - would have happened on its own, eventually, but this was an engineered process of rupture.

I also question your characterization of the phenomenon as "caring about one's heritage". It's one thing to take an interest in one's ancestry. That's perfectly fine and perfectly normal, but that's not what is at issue. I can look at my family tree and note whatever ancestors of other ethnic backgrounds there might be. It's another to claim as heritage and as identity some culture that your family shed generations ago. Culture is lived in a society, not a gene you inherit.

(Incidentally, this is why some Black Americans dislike the term "African American". Black Americans have been in the US longer than most Americans of European ancestry. They aren't "African". They're a cultural group that emerged in the America South. The case is similar with Jamaicans, Barbadian, St. Lucians, etc.)

> What I would ask you is why does it irk you, why do you care?

How about: why are you so bothered by this observation? It seems quite personal to you, which should perhaps be something bracketed if you wish to be objective.

> People of Italian ancestry in the US did not forget everything about their past

The most you can claim on the basis of these residual bits of knowledge and culture is Italian influence. Just because the Boston Brahmins know their English ancestry, or have English ancestry, doesn't mean they're English.

An "Italian American" generations removed from Italy is not the same as an "Italian", and so on. That's not a denial of influence or origin. It's just factually incorrect to say they are the same. Culturally, they are not.

> Comes off as gatekeeping people who would otherwise be your relatives.

It's interesting you call this gatekeeping. I am not the cause of such facts, and so I am not the one drawing up the boundaries of reality. I am merely recognizing them.