Both Swords and Blunt Weapons(Maple Story Mesos) have their pros and cons, and the overall majority of White Knights are swords users. But, Blunt Weapons have their own Advantages as well.
Very Popular Weapon. Warriors have always been associated with Swords.
Swords have Stable damage and will produce the same kind of damage constantly to monsters.
Generally very expensive to buy in game(Maplestory powerleveling), and to scroll.
Rather commonplace weapon to use, about 85% of GMS who have a White Knight or Crusader use swords, which can generally be boring to some.
Blunt weapon Pros:
Blunt weapons are stronger then Swords.
Blunt weapon users are rare, and so being one of the few give you a certain degree of comfort.
Very Inexpensive compared to Swords and to scroll.
Blunt weapon Cons:
Blunt weapons have unstable damage in Maplestory, and so the amount of damage a White Knight will produce will be at random.
Blunt weapons are slower then Swords, this is why using them is generally frowned upon.