Why anyone would willingly travel to the third world amazes me.
You don't know what the hell your talking about. They are one of the largest global economies. I take it your still on your parents tit in the Mandeville bubble.
I have worked down in Brazil quite extensively (Hornbeck, Chouest & Otto Candies) Think of Brazil as you would Louisiana. Good parts and bad parts and sometimes the dividing lines can be quite narrow. Crime is out of control like New Orleans, but good situational awareness will greatly decrease your chances of a bad encounter.
That being said, I don't know how Rio landed the Olympics. The infrastructure makes New Orleans look modern and cutting edge. The subway is nice as are the Higgins, NOLA built ferry boats between Niteroi and Rio. Copa is getting worse and Ipanema is a much better area to stay at.