Well on European servers most people are usually German and don't speak much English. Unless there is a German server. On euRO and WonderKing EU for example you basically talked German by default because it was more likely that the people you talk with speaks German than English. If the person signalizes he/she doesn't talk German I of course can also talk in English with him/her. :-)
Language barrier shouldn't really be part of "bad community", though. It might be that a person just seems to be stupid to you but if actually pretty intelligent and just doesn't really know your language/english.
In games that look fairly cute the main problem is that there are many young gamers. But even those are not all stupid. In WonderKing our guild leader was only 13 years old and he was fairly intelligent and helped everyone in the guild a lot.
That being said I really often have problems with communities. Especially on games that have been running for a while. Many players are too "elite". This is not in all MMORPGs either, though. The worst communities are those that are pretty much non-existant. Where you run around and don't see a single player. You can't join instances because they require a full party but you can never find enough to do it with you. That's horrible.
