Can we discuss Darrow's morality- Morning Star spoilers

I have reached a scene at the end of Morning Star which I'm sure is infamous, Darrow trying to release Cassius and being betrayed. I cannot bring myself to read further without getting this off my chest.

The thing I don't understand about this series I've been enjoying is how Darrow judges people. Cassius is an unrepentant Gold supremacist who has murdered countless people to maintain oppression. Darrow knew him for literally a month before being backstabed and butchered like a dog over the Passage, completely unreasonable hypocrisy. At this point Darrow had every reason to hate Golds, and did hate many. Leto, Jackel, the Proctors, the Sovereign etc are all correctly judged as monsters who need to be cut down. Cassius joins their rank with countless misdeeds, including direct involvement with the deaths of Howlers and Ragnar. Objectively he is no better than Jackel or Aja.

But Darrow's morality seems to hinge entire on an intuitive judgement of one's inherent goodness rather then their actions, and whether they were personally likeable. No matter what he actually does, Cassius is good because he has a 'good heart' and good memories with Darrow (for literally one month is highschool), Jackel is evil was he was born a psychopath and was his enemy in highschool. Rouque got the exact same treatment. After killing potentially millions of members of thew Rising Darrow was willing to kill him, but considered him a 'noble, kind soul' to the very end. He wasn't. He could have been an actual poet, but he chose to dedicate his life to oppression and injustice.

Darrow has this single bizarre blindspot that rather than a character consistent trait, feels like reflect a problematic worldview of the author. People are inherently good and no matter which side you pick or what you do, that never changes. It appears is more places, Julian was constantly described not has someone who did any particular actions that was noble, but an inherently 'kind soul good for this world'. Was he? How? Did he treat lowColour's well, was he self-sacrificing with his friends or a Reformist? We'll never know, because to the author it doesn't seem to matter.

After Darrow starts making insane mistakes, this goes from a pet peeve to a glaring issue. Releasing Cassius was an insane, irresponsible, stupid and comically selfish, a betrayal to everyone he cares about for a man who did nothing to earn it. It was a spit in the face to Ragnar's memory, and real problem I have with it is the that Sevro (rip ;-;) and Mustang somehow agreed to it. If it was Darrow's character flaw that would one thing, but the entire plot bends and everyone acts out of character to accommodate this bizarre inconsistency in normally reasonable characters.

Look, I'll bring myself to keep reading eventually but I really would appreciate other perspectives on this, I would love to be proved wrong and go back to respecting this characters but man, it's hard.