Brazilian bureaucracy is often frustrating. Any Brazilian bureaucracy, for citizens and foreigners alike. I feel your pain, having experienced various incidents. All I can think of in your case is applying again and asking to speak with a supervisory level consular employee.
However, as to why they may be so infuriatingly picky........I answered questions about Brazil on another board and the vast majority (at the time Brazil's economy appeared to be doing quite well) were from Indian men without resources to show, asking how to get a visa, any visa, to go to Brazil with the intent to marry some woman (presumably also poor and desperate, and from a country where arranged marriage is almost unknown) the man had "met" on the Internet and corresponded with for some brief time. Clearly, a country that has far from full employment for its own citizens has reason to be careful whom they admit.
Obviously to us here on this forum, Brazilian officials should be able to differentiate between economic classes, and understand that Brazil is not so attractive in these present economic times, but perhaps stereotypes still rule.
Best of luck in getting your visa for the Olympics.