I believe a reason for keeping it like it is with 2 swings is due to it's length, weapons that long are horrifying to fight against if they have side swings. Ever remember trying to fight the bamboo spear in native? Same idea, once weapons get over a certain length they just become silly, they can be easily abused without any form of skill. For example a player is commonly on the duel server with full plate, full strength and a scythe; he just jumps backwards and spams the scythe, it is not only frustrating to see him beat the top duelists on occasion with this style, it also looks terrible.
I would vote against giving this weapon 4 weapon swing directions, but instead perhaps give it the opportunity to occupy an economical halberd role (cut overhead strike and pierce stab). It seems to be in this role at the moment in stats, just maybe the stats don't make it worthy for this role so perhaps balance it.
Poll