Everyone avoids talking about race and the genocide of indigenous peoples because it is embarrassing to talk about historical crimes. The reason why so many Italians immigrated to Argentina, starting in the mid-1800s, was because there was more "room" in Argentina to absorb them, given that the physical elimination of the indigenous population in Argentina had gone further than in most Latin American countries. (I would argue that we Italians were not a part of that crime, which happened before we arrived in Argentina in large numbers). The indigenous peoples of South America survived at higher altitudes, protected by the mountains (Andes) and their remoteness. Argentina had more flat land (Pampas) and less mountains territory than most South American countries - ergo few places for Native Americans to hide. (Unlike for example neighbouring Paraguay which has always had few Europeans, being the South American "Israel" for Native Americans. The Jesuits, btw, created Paraguay as a haven for Native Americans.

As one final comment, Colombia was named for Christopher Columbus, Venezuela was named for Venice... there are large Italian communities all over South America - with the only exception being the Guyanas. In fact, there are a surprising number of South American presidents over the last 150 years who had Italian ancestry. And, from Alaska to Tierra del Fuego, Italian is the fourth most spoken language in the Americas (ahead of French).

According to the Italian government, there are 31 million Brazilians of Italian descent. Brazil is home to 30 millions Argentina 20 millions United States 17.800 millions

The whole discussion fails to point out that there were also differences from the sources of immigration inside Italy.

Most immigrants to the US were immigrants from southern Italy, which began to industrialize later.

In Brazil, most immigrants were from northern Italy, which was industrializing earlier. Veneto, Trentino, Lombardia, etc.

There was also a difference in immigration pattern between immigrants to São Paulo and southern Brazil.

Immigrants to São Paulo mostly stayed in the city, which was already catching up with Rio de Janeiro in population and importance, or in coffee plantations, while immigrants to the brazilian south were making their own settlements and having their own land.

While italian immigrants to coffee plantations in São Paulo were probably being mistreated, in southern Brazil they were owning their own lands and creating their own cities and companies.

Moreover, even in São Paulo, the situation was probably not as bad as the propaganda in Italy made it seem.

Many italians in São Paulo were not only becoming successfull as also quite rich. While in NY at the beginning most rich italians were associated with the mafia, in São Paulo, by 1927, the Martinelli building, São Paulo's first skyscraper, was built by a rich italian immigrant.

And while NY had the powerful Rockefellers, São Paulo's most rich and prestigious family in the first half of the 20th century were the Matarazzos, also from Italy.

https://en.wikipedia.org/wiki/Count_Francesco_Matarazzo

"At the age of 26, when Italian emigration to Brazil was widespread, he moved to the city of Sorocaba, São Paulo with his brothers, wife and children. Initially he sold oranges and lottery tickets and shined shoes, reinvesting the proceeds in new businesses, eventually including plantations of tea, coffee, corn, rice, rubber and cotton.[1]

In 1890, he moved to São Paulo and with his brothers, Giuseppe and Luigi, founded Matarazzo and Irmãos. He diversified its business and imported wheat flour from the United States of America. Giuseppe took part in the company with a lard factory in Porto Alegre and Luigi with a deposit-warehouse in São Paulo.

War between Spain and Central American countries made it difficult buy wheat flour and he obtained credit from the London and Brazilian Bank to build a mill in São Paulo. From there, his business expanded rapidly to a total of 365 factories[citation needed] throughout Brazil. The conglomerate became the fourth largest in the country and 6% of the population depended on its factories in São Paulo.

The Gestapo spy Hans Wesemann reported that:

An entire fleet sails under his flag. Tens of thousands of workers toil in his factories. He makes cement, cuts down trees and turns the pulp into paper, on which he prints his newspapers. The public drinks his beer and watches films in his cinemas. He contrives to be both wealthy and popular and when the president of Brazil visits Sao Paolo, he calls upon Matarazzo first.[1]

In recognition of his financial and material assistance to Italy during the First World War King Victor Emmanuel III conferred the title of Count.

Matarazzo died in 1937 after an attack of uremia. At that time he was Brazil's's richest man, with an estimated fortune of 10 billion U.S. dollars

One thing that may have been a big factor is the climate. Argentina is the one place in South America that has large areas of temperate climate. This allowed Europeans to go there and find not just temperatures and weather they were already acclimated to, but that allowed the kinds of agriculture they knew.

The other large temperate areas available are in the United States, Southern China, the East Coast of Australia + New Zealand, and southern Africa.

Of those, the USA also experienced a large amount of Italian immigration in this same period. The British controlled South Africa, Australia, and New Zealand, and Dutch the rest of southern Africa, which may have served to deter other nationalities from settling in those places. China already had more than enough Chinese people living there.

According to the link above, a large number of the people emigrating from Italy during this period were rural folk from south Italy, so being able to carry out their agriculture would have been a huge deal.

The newly created Italian constitution, drafted after unification in 1861, heavily favored the North. This caused economic conditions to considerably worsen for many in southern Italy and Sicily. Heavy taxes and other economic measures imposed on the South made the situation virtually impossible for many tenant farmers, and small business and land owners. Multitudes chose to emigrate rather than try to eke out a meager living.

To take off on the climate answer, it is noteworthy that the area between Buenos Aires and the Brazilian border (to the north), approximates the southern latitudes of Italy's own northern latitudes. Thus, not only the temperature, but the rainfall and crop patterns of that part of Argentina resemble that of parts of Italy. Basically, Italians felt "at home" there.

In the U.S., the Labrador current makes places like New York City (where many Italians settled) much colder than the same latitude in northern Italy. The parts of the U.S. further south with similar climates (e.g. Virginia and the Carolinas) were much more "Anglo" and Protestant and much less receptive to Italians than climatically similar areas in Argentina (whose "settlers" spoke an Italian-like Spanish, and who were mostly fellow Catholics).

Also, Argentina was the most technologically advanced South American country in the late 19th century, while Italy was less advanced than the rest of Europe and the U.S. Put another way, they were quite "compatible" in this respect, being at similar stages of development.