I understand your point of view, its a little different of mine but still I have my arguments. I know people who have talked with me about this, someone of them are offended and a little tired of it.
Plus, that guy didn't generalized but his acts show the opposite:
This is like if i though that 90% of the portuguese people were stupid so I would start to ignore all of them because 10% its a really tiny chance to meet one nice portuguese.
Imagine this scenario
[Iambrhuehuehue] says: I would love to join you in this amazing Raid, I'm a DPS.
[Ihatebrs] says: I'm sorry, your name looks like Brazilian to mee, I would not like to have you in my super amazing raid.
Isn't a little racist seen that way?