South America countries have an entirely different culture to ours.
There are many ingredients that make up a derby.. geography, politics, religion, cultural beliefs, class, success (competing for trophies.) when you look at the Old Firm you see two teams in the same city. Add to that they are the two most supported teams in the country with the biggest followings. They compete exclusively year on year for the domestic trophies. Throw in religion and the sectarian divide, the politics, class and cultural differences any you have the perfect storm in my opinion. there are many great derbies, some have 1 even 2 or 3 of the above, I'd say with confidence you won't find another with all of those ingredients.