Quote Originally Posted by Irenia View Post
When BLU was revealed, they specifically said that their damage calculations do not take weapon damage into account at all, and that there is a higher weight on intelligence than other caster's to compensate.
It does take weapon damage into account, it's just that the weapon damage is 1 (the minimum possible).

I interpret the "increased weight on intelligence" to be the traits which buff the damage and healing potency beyond what it does for other casters. This has the effect of buffing intelligence.