People in Brazil are angry about the money being spent on the World Cup when they are struggling. They don't believe the promised profits will appear and definitely don't believe they will trickle down to benefit ordinary people. Ironically, all the protesting about that is likely to put people off going and reduce income....
Football is massive in South America, so I doubt they will have any trouble filling the grounds for matches, but whether tourists from further afield will fill the Hotels and boost other local businesses remains to be seen.