I don't know hardly anyone in the US personally that's racist against Brazilians. Not to say that they aren't out there, but I don't run across them much.
You hear some disparaging comments about people of Mexican descent, Indian descent, and African-American descent, but most people think Brazil is kind of cool. This is also due to people loving soccer, UFC, the beaches in Rio and Bossa Nova.
In addition to this, the FGC is like 50% minorities. Probably half the guys at Semij and Xinok's level or above have Puerto Rican, Dominican, Central American, African American, Middle Eastern, or East Asian etc. ancestry. Caucasian guys are usually the minority in Top 8 in every FGC community except Smash.
Anyway, I think it's a pretty big leap to assume this was an act of sheer racism. Not saying it's impossible, but the FGC is the one of the most welcoming gaming communities to people of all colors that I have ever seen.