is very permissive about granting citizenship, especially if someone can demonstrate somewhat recent Italian ancestry. So when all European countries limited clubs to somewhere between 2-4 foreigners, Italy would give Italian passports to many foreign soccer stars, especially Argentines (most younger Argentines have a the least one Italian ancestor) but also many Brazilians, Uruguayans, etc, and therefore get around the limits on foreigners.
After Bosman, that advantage mostly disappeared, because players with Italian passports could play anywhere in the EU without counting as foreigners. Over time, most of those Italo-Argentines and other naturalized Italians moved to Spain, England, Germany, and elsewhere.