To Klonoa's point, if it is all their fault, as in everything in the setting, and truly as black as you say, then why let them live? Wasn't Zenos enough of a lesson, of letting your enemies live long enough to foster the strength to come at you again. Are you going to be satisfied with them coming back into governance after they are inevitably crushed? Are you willing to let them choose a decision that you may not agree with?
If you cannot find something to relate to, either you do not know enough about them, or you know all you care to. It sounds like you are arguing that they are irredeemable, while at the same time sparing these irredeemable people for traits you don't believe exist in them... Is that the case?
I do not see it as all their fault, especially with the primal problem given the setting and their limitations, so the point is pretty much moot to me. I'm aware that there are facets about that society that need to change, much like Ishgard when we first went there. I'm waiting for the sane representations of Garlean government to appear on screen as well, as I know they exist, and that npcs from the empire have discussed about them. Indeed, they couldn't have an empire without it.
But if you cannot see anything worth relating with them and do not see it in the future then calls for their annihilation are bound to exist.
Edit: I'm thinking (hoping really) that we are arguing the same point. I haven't looked foward to this conflict.