DDO has 3 major categories of physical attacking that players do:
- Melee Weapon
- Projectile
- Unarmed
Melee Weapons have their properties come from the items themselves. Projectiles use a combination of the weapon and ammo (or in the case of throwing weaponry, just the ammo). Unarmed gains properties through the player via pseudo-buffs that trigger on unarmed strikes. Because they gain their effects from various sources in different ways this leads to some effects working on some of these attack methods and not others when bestowed from non-standard sources, such as armor or a buff-like effect.
For whatever reason, Destruction granted from non-weapon source only works on Melee Weapons currently. It was never altered to be compliant with ranged/unarmed attacks.