Am I an asshole?

I feel so guilty for judging my siblings for the way they treat my parents. My parents are horrible people, I thought I had come a long way and that I learned to separate myself from them, but even after all this time, I keep thinking about them and worrying about how my siblings treat them.

Everyone reacts differently around trauma and abuse, I feel as though I've grown to normalize it towards myself, I expect people to hate me and point fingers at me while laughing, in a way, it's like telling myself that I'm the problem when I was the child being abused. I've dissociated their actions from them and now any time I remember how i had my head bashed against walls and body bruised up, I can't remember how they looked doing it. I also realize that a pattern appeared, that whenever we fight and it gets physical, I end up the one clinging to them and giving them affection.

My siblings are not the same, some of them are violent, I get why, and they vary in the severeness, my eldest sister whom I never even spoke to properly once in my entire life, resents my parents alot, my other sisters always tell me about the things she says about them, and even though both of us endured the same pain, we grew to have much different outlooks in life, and i feel like it's an instinct for me to feel repulsed anytime I hear how she speaks with our parents, I even judge her in my head, but seconds later, I realize it and feel extremely guilty

I guess even though my parents are horrible, a part of me understands why they're so fucked up in the head, my mum was literally born in an extremist traditionalist family during a war and my dad lived in poverty having to take responsibility of 13 siblings because my grandfather was a manwhore. They both endured so much and pretty much no one present in their life to be their anchor. I cant be mad at these people, they suffered so much, they're old now and fighting them just gets both parties hurt so I just stepped out of the house and went low contact with them. I don't get why my eldest sister bothers herself so much with them, or even go to such lengths to talk so horribly about them. I guess I'm still a prisoner in that house, because I can't find it in me to hate them the way she does,,