Not only that but parent comment (which does make some valid points) doesn't take into account what could be called the reverse network effect. If stories of facebook's lack of popularity continue to surface (as well as the reasons for it) things would begin to accelerate (stock drops, advertisers no longer see it in a positive light) users who wouldn't leave begin to leave or discover alternatives, someone is spurred on to develop a product which attracts more of their users etc. In other words usage drops, morale at facebook drops it's no longer the place to be. Facebook hasn't been around that long and after a while it is entirely possible that even users today will tire of it and move elsewhere. And losing the network effect will make it less valuable to anyone who sticks around.