You entirely missed the point—it's not a matter of whether or not the content can be completed and entirely one of whether or not the game feels populated to newer players, which is important. There are people who don't stay on servers or games that feel dead because one of the biggest parts of playing a game like this is socialization.
Even WoW did a bunch of things over the years to try to encourage players to be "out in the world," though a large majority of them failed spectacularly and from what I can tell they've largely given up on it.
