Why do people just assume parents are always right and nice?

I've opened up to people about my parents or complained about out disagreements (not to randos, but friends) and they always assume that parents are right and im probably overreacting and being a brat. it really annoys me and i feel misunderstood so much!!

once i was talking to a senior. he always assumed i was just an angsty teen. one day we were having a bit deeper convo and being emotional i told him about ny past and how my parents are and other incidents and that was the first time i actually saw him take me being a troubled kid seriously. like he realized what I've been kinda joking about or projecting wasnt just performative but came from actually abusive environment.

Idk, anyone you complain to about your parents always just side with parents as of their children are dumb f*cks and don't have critical thinking skills