With unlimited modding capabilities there are inevitably unlimited possibilities for arguments over which mods destroy the game's balance and which mods are harmless. A prime example of this is the Advanced Idle Pointer mod for Age of Empires 2 by Gallas and linetyreborn. While it is inherently useful for new players, it might be considered just too useful by purists. In a centralized ranking system these disagreements can ultimately lead to a community split.
Idle Pointers: Genius idea or the downfall of civilization?