Except that you're incorrect. Sunbreaker's primary purpose in PvE is the ability to clear large amounts of adds. Nerf the AoE, or the Damage Resist, or the Health Regen, and they are no longer able to "jump into the fray" and clear the room. Instead they'd be forced to play a ranged game which makes the parabolic nature of the hammer even more of an issue. As a Titan, you try and get the Black Spindle without Sunbreaker. You'll never clear adds fast enough.