I believe the only modern Olympics to make money were the 1984 LA Games. Generally speaking the Olympics are an economic hole. Tossing such a burden onto the back of a developing country like Brazil while it finds itself mired in the worst economic depression in a century might not be such a good idea. (They did ask for it of course.) Heck, even some of the athletes are bailing on Rio at this point.
(From The Independent)
Some 300 police held a rally on Monday rallied to protest unpaid wages and unsatisfactory working conditions.