Current Factions are not fun, as they do not really impact the rest of the game.
If Factions had some real, lasting impact (as in the short-lived invasions) then I'd at least try it out.
Factions has always been an afterthought, I'd want it to be an integral part of the world that would make me WANT to fight or support them. However, I'd also want non-factions people to be able to fight all factions -- why should I have to pick one?