I didn't know what to explain when I got so annoyed by Good Guy Garon as a hack, but I think I at least have some kind of answer to that now, best summed up by Corrin's TV Tropes page:
* At Least I Admit It: Corrin stands out among the cast, who are steeped by various attempts to rationalize their actions as necessary for a greater good, in how much they absolutely refuse to diminish or ignore the human cost in their actions and are quick to take responsibility for the loss of other innocent lives, even the ones they couldn't really do anything about nor are necessarily even aware they could've done anything about. Corrin fully admits to (a truthfully possessed by Anankos) Takumi near the end of Conquest that he has every right to hate them for what they've done and that they're deeply sorry and doesn't make excuses for it; this is a reason why during Corrin's Near-Death Experience he and Takumi are able to forgive each other. Even when unavoidable massacres happen, Corrin is quick to demolish the possibility it needed to happen like with the Kitsune or Wolfskin massacres on Conquest and Birthright respectively. In a story that tries to have each of its characters frame their actions as somehow necessarily, Corrin is one of the only ones who are willing to admit and accept they're rightfully the villain in other people's stories, being completely non-plussed with the side they don't choose hating them for it. This ends up being reconstructed in all three routes, where it's Corrin's sheer willingness to acknowledge their responsibility in the human cost of the war that genuinely pushes their loved ones to change and be better as a result.
This is such a huge, crucial and fundamental part of Corrin's character that I genuinely act baffled whenever I hear people act like Corrin never suffers consequences when they try and take responsibility for things they realistically couldn't have helped. He genuinely had a justification for wiping out the Kitsune out of self-defense, and he genuinely had to engage in realpolitik and dealing with a bad situation in order to expose Garon as a fraud and break his siblings out of their trauma-induced denial while salvaging as many Hoshidan lives as possible. All of this is held up by the internal logic of the story as a whole. But he instead... doesn't do that. He recognizes he has hurt people and, by many people's standards, is the villain of others' stories. Half of the known world is going to hate him forever for this. And instead of preserving the narrative he's the good guy, he takes responsibility for that and recognizes the pain of what others' went through. It's such a fundamental aspect of what I love about Corrin's character, especially given the fact that even in his efforts to try and do what he has to to save the people he can, he notably doesn't let other people die due to shitty reasons; like him saving the Hoshidan royals from execution in Chapter 18 and turning against the Nohrian army, something that was plainly correct given not just the fact it was really fucking scummy and giving Garon control of Hoshido was not what anyone would've wanted, but doing it in a neutral DMZ is fucking insanity to say the least.
What bugs me about the Good Guy Garon hack (aside from the fact is misses the whole point of Garon IMHO that he's meant to be utterly warped because he wasn't even a person at that point), is that it completely fucks this over. At the end of Chapter 19, the writers "fixed" the scene into Corrin compartmentalizing the slaughter of the Kitsune tribe as somebody a good thing or necessary while Azura lays into him for not ending the war by killing the Hoshidan royals and prolonging "unnecessary suffering" as a result. Like, BITCH PLEASE??? So by "prolonging unnecessary suffering" means creating a succession crisis and letting Garon do whatever he want to Hoshido as a result?! Is she fucking insane?! Not only is it character assassination of Azura, it also completely misses the point of Corrin because his entire character is built on radical empathy and understanding others, which is undercut because most people genuinely cannot fucking admit that there's no rationale for them to hurt people no matter how much self-justification there is, which is crucial to FE Fates point. And seeing people talk of how "better" it is than canon when it flat-out removes such a core element really does not have FE fans beat the "I'm more mad at the unresolved contradictions that aren't pointed out by the story to me between the characters' actions and what they say, even when it's intentional, than I am in there being clear-cut good or bad" allegations.
It's just bad writing, and it's insane that people clearly do not fucking get this game because they're so fucking allergic to unspoken contradictions, even when they're the fucking point!
YEAH YOU GET IT YOU GET IT!
It's why I keep scratching my head and getting frustrated when people still make claims about the morality themes of Fates being falsely advertised or written differently or whatnot.
Corrin is not a blank slate whose morality is decided by what choice they make. They are a defined character with defined traits and experiences. Their beliefs and philosophy on justice, their idealism, their connections with their siblings, their pacifism, their unyielding will. Those are things that inform and develop them to make the decision on which country to back in the first place.
At a foundational level, Corrin was written as a character to think about their choices, to have regrets, doubts and waves of emotions about the things they feel they have to do. They're self-conscious, have humility and are extremely humble.
To write them as a person who goes out of their way to justify anything and everything they do before even getting accused of wrongdoing? That's a completely different character! Corrin is the person who doubts themselves first before anyone! They grovel about their mistakes, they cry over the deaths of people they just met, they despair constantly over things they may have missed or overlooked.
AND THAT'S FUCKING AWESOME! Why wouldn't you want a protagonist who does that? Who recognizes they have flaws or weaknesses and need to grow? Who approaches situations with such clear morality and idealism that you can never be mistaken or misled on how they feel about a given situation?
By making Corrin into a character who's okay with sacrifices or tries to analyze and distance themselves from deaths and destruction that they're involved in, they're just making an OC! One who's frightfully boring, on top of being pretty grating to listen to. What drama or conflict is there if the protagonist is so secure in their decisions that they never have to question themselves?
Thanks for the ask!
