In the context of justifying their decision to award the competition to Brazil in the first place. Brazil doing well (in the eyes of the Brazilians) will encourage the crowds and generate the carnival atmosphere, instead of (even worse) riots, tear gas and bad publicity. Perhaps.
I just think that, with all the issues surrounding the cost of the World Cup (didn't Brazil's bid say there would be no public money used?), the demonstrations, the readiness of facilities, the madness of Manaus as a suitable venue, FIFA desperately need this World Cup to be a success, and that...