Brazil is a very rich country, full of natural resources. It is not that there isn't enough wealth to raise people out of poverty As is often the case, there is massively unequal distribution. Although I agree that the money spent on the World Cup could be much better spent, the causes of poverty are systemic rather than relating to these sorts of grandiose projects.
We spent an absolute fortune on the Olympics and apparently we are the 7th richest country in the world. That isn't much comfort to people who can't buy food, pay their energy bills or find secure and reasonably priced housing. After the terrible floods, Cameron indicated that as a rich country he would be able to spend whatever was needed to help the people affected (mind you, there is an election approaching).