the aforepromised AOT analysis taken from my too-long tags:

There are certain characters who - had they been introduced as protagonists rather than villains - would have been beloved by their strongest haters. not because those haters would’ve excused their actions, but because their victimhood would’ve been the first thought, and not the afterthought. i am speaking of the Warriors once again. i feel it is important to note that, while Reiner may have had the mental breakdown, they were all raised under dysfunctional - perhaps traumatic - circumstances before they ever joined the Warrior program. especially Annie. holy crap let’s look at Annie for a second.

> born outside the internment zone. > discovered to be half-Eldian. promptly abandoned to the internment zone. > found by a bitter opportunist who abuses her from infancy into becoming the perfect human weapon. > one day, she cracks and beats him so badly she permanently cripples him. this makes him HAPPY because it means he’d succeeded. super normal response. > she is enlisted into the child soldiers program where the brainwashing gets cranked up x3000. she makes no friends and kills critters for...leisure? existential dread? > is forced to EAT A PERSON at 11 years old. at which point she knows she will die in 13 years. > is sent on a deadly mission at 11 YEARS OLD to eat MORE PEOPLE. as she’s leaving, her ‘father’ repents and begs her to come back. crying, she instantly forgives him, because obviously she is a child and this is the only parent she has ever known or wanted. but now she HAS to complete the mission because if she FAILS, she gets EATEN and her father gets KILLED. > on the mission, Annie watches as their leader (also a child) gets EATEN. she lashes out against Reiner in exactly the same brutal way she did her father. > when she tries to quit the operation, Reiner strangles her into submission. > Improvising without Marcel, Annie then transports Reiner and Bertholdt all the way to the Wall, at which point, she passes out from sheer exhaustion, and entirely misses Reiner and Bertholdt committing what is essentially a terrorist attack the likes of which we have never seen. an act of war and a mass slaughter.

> then, Annie assimilates into this society of monstrous devils who, to her horror, turn out to be merely frightened people. (this is the first place she makes a friend in her entire short life.) > Annie proceeds to complete ALL the mission reconnaissance herself, until she accidentally reveals her face to Kenny Ackerman. she tries to persuade Reiner to take the intel she’s acquired back to Marley, but he insists they must complete the mission if they want to live. > so, at age 15, Reiner & Bertholdt REPEAT the initial slaughter. > after Annie rescues Connie from a titan, Reiner essentially threatens to accuse her father of being a Paradis sympathizer unless she takes Marco’s 3DMG off him. > Marco begs her for mercy the whole time, and she cries as she sentences him to an agonizing death. > this is when she realizes Reiner has lost his mind. and maybe she will, too. > it falls to her to capture the Attack Titan. if she can do so, she will be allowed to return to her father. she jeopardizes this mission by sparing Armin’s life, not once, but twice. > she locates Eren (her first friend, the only person who’s made her genuinely smile) and, in her Titan form, decapitates his Titan with her bare hands. > she has killed everyone in her path, but she ultimately fails to take Eren, and cries when she realizes it was all in vain. remember, she is fifteen. > she is then tricked, cornered, and exposed by the last person she would've wanted to do so. the only person who’d ever called her kind, and the very person she'd made the mistake of sparing before. > in a fight she didn’t initiate, she accidentally crushes innocent churchgoers. this the first and only time she personally kills civilians, and it horrifies her. > she fails to capture Eren again. she fails a desperate escape attempt. > crying, she self-induces an indefinite coma on the off-chance she may be able to one day return to her father, knowing she only has 9 years left to live anyway. >  is actually awake the entire time, and can hear everything being said and done around her - including the silence - for four years. she is trapped not only in the crystal, but in her own mind, with her own guilt, for four years. her peers have spent them growing acquainted with relative freedom, themselves, and the rest of the world. but she is physically and experientially still 15, never having known anything but her mission and the internment zone. > she is forcibly de-crystallized into the middle of the Apocalypse. she has 5 years left to live. her father is dead.

So I dunno, maybe we shouldn’t be surprised when she says things a psychopath would say. maybe we shouldn’t be surprised that she single-mindedly clings to the one piece of human affection her 11-year old mind internalized. Maybe we shouldn’t be surprised when she behaves erratically or brutally while still seeming like a child at times. by all accounts, she ought to be way more messed up than she is. but Armin was right. in spite of her upbringing, in spite of her brainwashing, in spite of her mission, in spite of the world, Annie wants to be a kind person.