I'd also posit my unqualified opinion^1^ too: I think it's the idea that the rules are inconsistent. You try to follow a system that everyone says is "blind" and impartial, only to see it just got Lasik and is very, very partial to particular people. The dissonance between experiencing injustice and insistent claims that the civilized world is fair.

If all cultures codified that "money buys clemency", there'd be a lot fewer outbursts about how unfair things are.

^1^ I'm probably not autistic, just have a lot of autistic friends.