By racist they mean "being Italian means to be assimilated". But that doesn't mean that they mean to discriminate against them or to be unkind. Quite the opposite. Italians love to be kind to foreigners.
Italians welcome so many refugees from Africa... but in the suburbs so many foreigners don't assimilate, so they are not considered Italians.
The French and the Germans think these things, but won't tell them openly.
Italians think these things and say them out loud.
In the past, assimilation was a major component in U.S. politics regarding immigration. I think I've posted previously about how Henry Ford set up a school for immigrants which apparently taught them how to be "good Americans." Similar trends could be seen in the establishment of "Indian Schools," where Native Americans were educated in the "ways of the white man." Even freed black slaves gave up their slave names and chose names which they considered very American, which is why so many African-Americans have names like "Washington," "Jefferson," "Lincoln," "Jackson," picking the names of Presidents as a way of assimilating. It also affected Spanish-speaking communities, whose children were given corporal punishment in schools if they spoke any language other than English (it even happened to people I've personally known here in Tucson).
Over time, the idea of "assimilation" seemed odious and disdainful to people, as people tend to resist being told to give up their native language and culture. Also, people were still discriminated against due to skin color, regardless of how much they tried to "assimilate." (They had to pass what they called the "paper bag test.") As a consequence, open and firm resistance to assimilation also became a cornerstone of the Civil Rights Movement, which is why the very idea of "assimilation" is considered racist, even if it may (technically) not be.
This, in and of itself, has become a bit of a bugaboo in politics. I recall a few decades back, there were a number of states (including mine) proposing and passing "English-only" amendments, which were decried as racist. Advocates would argue back, "No, it's not racist; it's about language." Sometimes, statements like that are seen as creating a thinly-veiled "plausible deniability," where they can say that, technically, they're not racists, because their rhetoric does not directly refer to skin color.
They might use code words, or what some people have called "dog whistles," to indicate an agenda which I've heard called "stealth racism." At that point, the discussion kind of degenerates into a rhetorical "game" of sorts where the expected goal is "Ha! I caught you saying something racist!" I think that tactic has had the long-term effect of cheapening the discussion to the point where it's not viewed as seriously as it once was.
Europe and America had different histories.
Italy implemented racial laws just for five years, and to satisfy the Nazis' requests.
There has never been the segregationist mind...which is what Italians consider bad racism.
My impression of Italy is that there appears to be some elements of racism, as I've heard about rivalries between northern, lighter-skinned Italians versus southern, darker-skinned Italians. I once had a conversation with an Italian guy I knew from work, and I was telling him about a young Italian woman I had met in college. The Italian guy had darker skin and black hair, and when I described the Italian woman I met as having reddish hair and very white skin, his response was "She's not Italian," just like that. (Her surname sounded like it had German origins, so maybe that's what he meant.)
I've also heard some perceptions in Italy where they view everything south of Naples as "Africa." Of course, these are just things I've heard and can't verify personally, but it does seem to come up on occasion.