Very, very interesting thread.
As a minority (Chinese) living in the US who has traveled all around the world, it is interesting to note that people everywhere are irate with another certain group of foreigners. And it is interesting to note that most of the tour groups that give their nationalities a bad name are usually the youth groups. So why are we singling them out only for their nationalities, and not for their youth???
When traveling in Europe, I have seen American youth groups run around in church court yards and barging into cathedrals during prayers and cussing out the security at the Vatican because they were not allowed in because they were showing too much skin. I've also seen American youths speaking Spanish to retailers in Portugal (talk about ignorant!) and jumping and climbing on statues in garden, even though signs specifically asked people to not even touch them. Likewise, I've been shoved around by Italians, glared at by the Swiss, and treated with rudness by the Germans. And don't even get me started on the big Argentinian family groups on those Caribbean cruises! And where I live (Washington DC), I see Asian tour groups literally take over the city in the summertime, and believe me -- I mean TAKE OVER.
So, in other words, there are rude people everywhere, and there are polite people everywhere. I don't think it's fair for us to single out just one nationality; however, I can see the OP's point of view. Perhaps the Brazilians travel to WDW en masse during a certain time of the year, so they are more visible. For instance, the Chinese may be just as rude, but because their tourism season to WDW is spread out over the year, rather than converging on the park all in two months, they are less noticeable, kwim?
Frankly, I've found it worthwhile to stand up to such rude people. In Portugal, when I heard the American speak Spanish to the retailers, I did not hesistate to say, "They speak PORTUGUESE in Portugal." And I yelled at the kids to stop running around the church and show some respect, and they were as quiet as mice after that, and some even came to apologize to me. And the Italians who tried to push their way in front of me in the bathroom got a good shove back from me and a bit of swearing in English -- who cares if they understood me. Stand up for yourself, and more often than not, these bullies will back down. Don't let them ruin your vacation for you!
Linda