I used to think it was a bit rude. But then I simply got used to people nattering and realised it was just a part of the general social crack. Though I tend to be a listener rather than a natterer myself, it doesn't bother me if others talk. A low level hum of conversation in a corner here or there doesn't bother me so long as the mood is amiable and everyone's having whatever they find to be a good time.