Well, again, you reach a point where factions of players will be made into losers of a conflict they had no part in through no fault of their own. Enough ‘cold conflict’ will eventually have someone demand a spark and then it worsens for everyone.
Factions are fine for PvE purposes and storytelling, but things get very bad very fast once PvP infiltrates the narrative and especially if it has tangible effects on the world.