French, Polish, Brazilian people are notoriously hostile, in every Multiplayer game i ever played.
If you get a whole guild of them, they will troll and cuss anyone not in their language exclusive guild, and if you ask them to communicate with you in eng, they will take it as an act of war, and go out of their way to gank you, if possible.
Ofc it's not all of them, or even most of them, but those that do it, ruin the reputation of an entire country.
I've chatted with lots of very friendly Brazilians though, and a few of them were very happy to chat with me, and felt that their English improved from it; same with a French guy, in D2 - he said his eng grades dropped, when we lost contact for a while
I think some people from these countries, are just extremely patriotic when it comes to their language - refuse to learn Eng, and get offended, if you ask them to speak it - It's not like you see Swedish ppl go bananas if you ask them to speak English - they just happily oblige, and apologize for alienating anyone.

Anyway, this is common on every EU server, in every MMO, not just here.