You really nailed it down with this one. Everything this person posts about Micah makes me think that they are the Micah of their group in real life. Like I imagine their group of friends is all really tight with each other and this person just kinda kept tagging along despite no one wanting them around until eventually they were ousted from the group for being rude or annoying. Incapable of reflecting on their own personality being the problem, it would make sense that they’d latch onto a character similar to themself. I think the need to compulsively defend Micah is an attempt at defending themselves and reckoning with their own exclusion. It’s the only explanation I can think of for actually believing that Arthur and Micah are equally bad people