There is so much corruption in Italy. The country continues to suffer high levels of corruption higher than Spain. According to the Corruption Perceptions Index by Transparency International, Italy has about a 20-29 level of corruption which is really corrupt.
https://en.wikipedia.org/wiki/Corruption_Perceptions_Index
Secondly, aren't immigrants supposed to engage in nation building by building up strong institutions, government, and industries? That's what nation building and immigration is for.
Article 25 of the 1853 Constitution: The Federal Government will encourage European immigration; and will not restrict, limit, nor tax the entry of any foreigner into the territory of Argentina who comes with the goal of working the land, bettering industry, or introducing or teaching sciences or the arts.
Thirdly, Argentina would be governed with a different mindset if French immigrants came into the country. The country would industrialize really fast and greater economic development would happen in the Pampas. The government would be managed correctly and there would be greater transparency and strong justice system. They would not be despotic as well. It sometimes doesn't have to do with institutions. It has to do with the mindset of the people. The French have a strong mindset and commitment when it comes to economic development, low corruption, and a strong government better than the Spanish and Italian people have.