The MAJOR debate over Holy Arrow

As for Holy Arrow, it's worthless. If you max all other 2nd job skills you'll have lvl 11 holy arrow. Those other skills have more of a long-term impact than Holy Arrow will. When you are training on strong undead monsters, Heal is a better attacking skill because it hits a lot of monsters and often lets you train without MG. MP Eater becomes worthless later on. But when I was training at Hoodoos and Voodoos, MP Eater allowed me to train completely without potions, which I liked.

I think his post best describes whether one should max holy arrow or not. Adding to what Quantact said, not maxing HA gives the player more pts to max the other skills that can carry over it's usefulness right until the 4th job. Btw i'm not debating how useful/bad HA is, but by maxing HA, you will not be able to max one of the following : MP Eater, Heal, Invincible, Teleport, Bless.