Doesn't this makes more sense for Raids.
You also miss around 8% critical damage from ferocious winds and vulnerability from Weak spot. With staff you should usually run Inscription over Aeromancer’s training anyways, this trait is pretty insignificant but will decrease the cooldown on glyph of storms.
Vulnerability will be capped in raids anyways, and one could argue that you can build a team composition where bountiful power slightly outperforms BttH and Ferocious winds. I doubt it will be consistent though.