The thing that gets me is that the dominant prestige for rogues is called Assassin.
(dictionary.com)
noun
1. a murderer, especially one who kills a politically prominent person for fanatical or monetary reasons
And yet rogues are now terribad at killing prominent figures. They're second only to casters at killing trash, but that's not an assassin's role. An assassin would ignore the trash and instagib the boss. The only balanced way to approach that is to reduce or eliminate fortification, so at least he's dealing a ton of damage to it.