Socialism in Latin America is relatively recent. They became ‘independent’ after the Bolivarian revolutions of the 1820s, on the aftermath of Spain’s and Portugal’s occupation by Napoleon’s forces. The first ‘socialist’ movements in there only came after WW2, that i know of. That’s more than one century of history in between., before any “socialism”.
If you want to understand the modern ‘socialism’ in Latin America, it’s best to start with the Cold war situation there, and that requires an understanding of the socio-economic conditions already existent since the formation of those countries, and their development through more than one century.
Regarding their hatred of mistruist for “imperailists”, mainly Spanish and North-Americans, that’s very easy to understand. Read about the American “Monroe Doctrine”. In the late 19th century, a large fraction of the economy of many of those countries was owned by american companies. Many of the wars and political manouvering that happened there for the past century and half were over economic interests of those companies.
More recently, the widespread intervention of the US during the Cold war - Operation Condor, various coups, military interventions, civil wars, etc. Bolivia is still one of the countries that receives the highest military funding from America.
There were even some guys, like one famous William Walker, who tried to create ‘personal’ kingdoms for them in Latin America. That walker hired an army to establish a “republic of nicaragua” for himself. It was lots of fun and aventure, at the time.
And Venezuela? As recent as 2002, the US supported a coup d’etat against Chavez. Guess which single other country recognised the coup? Yeah, Spain. Obviously.
If any country supported a coup against the US government, we would have a 3rd world war, or some new “war on terror” 
The history of Brazil and Argentina is relatively particular and distinct from the rest of the continent. Brazil, Argentina and Chile were big economic giants at the turn of the century, as developed as Europe, and major destinations for European emigration. That ‘special situation’ eventually evaporated, and it’s debatable why.
Internal strife played a part. The Brazilian economy was mostly made up of large landowners, and they were many conflicts against/around this feudalistic aristocratic class. The strong isolationism of Brazil also didn’t help. Argentina too became increasingly isolated, especially after WW2
