Since people more eloquent than myself have focused on the problems with defense itself, I'll be brief.

Quote Originally Posted by Camate View Post
Naked/with Defender active/with Defender active + food effects (black curry bun)
Because dealing damage is the most effective way to increase enmity in today's FFXI, this person has a far more effective method of damage mitigation than defense available. This person will never be targeted by a monster on which any effective damage-dealer is engaged.