I think that in a fantasy world scythes should be used by priests especially ones bent on killing the undead. You might think that necromancers being related to death and all that should use them, but the scythe is a symbol of destruction, of subtracting, of cutting down. While necromancy is exactly the other way around it's bringing life to corpses. Death probably doesn't like necromancers because they get in the way of his job. I know your thinking scythes wouldn't fit with church and priests but if you have a farmer's scythe wielded by a humble monk who worked at a farm it could fit in quite nicely.