Yeah, because that's gonna help when the whole world is being blown up.
The focusing iris' power can pretty much be summed up by one of Malygos' quotes: "The powers contained here are sufficient to destroy the world ten times over". Now of course he was talking about the Eye of Eternity all together, but truth is that the Focusing Iris was the eye of the storm.
That's like saying that a Warcraft Abomination is the strongest form of humanoid just because it's made of multiple other humanoids. Obviously it isn't.
In all honesty Deathwing takes this, not every dragon can simply blow up a planet.