Patriotism should be dying, to be honest.
It's the mindset that we're on one team and we are some united people that don't let other people from a separate section of rock join us/take pride with us, which is the same mindset cultures thousands of years ago had, and this process has lead to billions of people being murdered and their lives stripped from them for such silly ideas over these thousands of years.
Like your example of Brazil, they mindlessly vote for and irrationally support their own countries fighters, even if they are jerks, even if they say stupid stuff, even if they do this or that, they support them, simply because they come from the same section of rock. It's this mentality that makes people kill each other over rocks and dirt, where even if something is bad or crap about this rock and dirt, they blindly support it and ignore it for the sake of by a small chance they just so happened to have been born there.
The "one team" mentality should be going away, people should connect on a much higher level and be a lot more social with each other, that's the next step of social evolution in my opinion and it's showing through the likes of social media, connectivity around the world, etc, and the result is less patriotism and less respect for a piece of land they just so happened to have been born on.
I do not think that's WHY people are not supporting America, in fact I don't think that even crosses anyone's mind when they are not placing their hand over their heart for the anthem or whatever. I fully believe it is a direct result of this "one team" mindset, however, and I for one am glad it is starting to fade out.
edit - I fixed your video Mmawrestler,