It's a known fact that +%dmg gear is better for dealing damage then any of the other gimmick effects available now.
why doesn't the item level on the +%dmg gear reflect this fact, because at this point it is a fact.
for a dps class +%dmg gear is always going to be better for doing their role, which is to dps, and even for tanks it helps them to hold aggro.
It makes no sense that some of the most useless gear in the game has the highest Item Level.
who does that?!