Factions need coordination, talk and disputes.
Most people do not want/know how/are able to use mumble, ts, etc.
Lobby faction channels and their "secret topics" are easily readable by other players.
In 0k lobby there is of course channel history, but we all know that, hmmmm, content of chats is no permanent.
That's why we need dedicated subforums for each faction, we know that there are faction forum threads, but it is actually worse than lobby chat to dispute. And such subforums allow separation of different disscussions. Even better idea - subforums for factions and another subforums accessible only by faction staff.