(Swore it said "faction.") The label aside (that you can find who the top players in a game are by who has those achievements and such that nobody else has or tried to get, usually about 1% of the population), I think the point is valid. Those that are always grinding for the top usually do so and come back the next world, anyways. My opinion is completely subjective, as I don't have access to data to form a truly objective opinion or provide information on who does and doesn't stick around. It certainly is going to be skewed because there's quite a number of players that don't pop into the forums here, either because they play with a few personal friends, they don't read/write English, or this type of communication just isn't important to them, or whatever other reason there might be.
Nope. They are doing it for themselves (and that's fine, that's how proper passion project should be anyway).
