I think it's necessary to decrease the negative parts of realism. If you wanted to organize an event such as a tournment, or if you wanted to give a speach to the city, in real life you'd have to put up posters days or weeks in advance. With the buddy list and /guild chat, things happen a lot faster and a lot more easily, even though the communication is highly OOC. Plus it makes helping new players easier, and staying in contact with friends about various issues.