I suspect Minecraft has a much harsher profile, since it's possible for every player to be loading a different piece of the world with minimal overlap, and world-pieces involve a lot more state that needs to be preserved/calculated/saved.
Think of two players running towards each other, and shooting at each other. By the time the player (or even the server) receives the data saying the other player has fired their gun, they've both moved to completely different positions.
(There is a good set of articles on this by a game developer, I can't find them now)
The world pieces are a very specific set of permutations, which could easily be loaded in to a graphics card's memory at the start of the game. All you are really tracking are which pieces are where, and by the game's nature, there aren't that many pieces or positions they can be in...
https://github.com/SirCmpwn/TrueCraft
May give you some insight into how Minecraft multiplayer (or any other detail of Minecraft) works. The server code is in the TrueCraft directory.
