Also, i wonder why its always the ones who's parents are rich or has a steady position that always end up being the rotten one, lol.
I'll distinguish between IRL examples, and the exaggerated fictions in manga. But I think this is a real life problem, and it's a consequence of social hierarchy and material privileges like income inequality or private schools.
I can speak on this better in western society, as a westerner, but one of the root cultural beliefs is
Calvinism. Calvin said that God has predestined a select few to get into heaven, while the rest are doomed to hell. We can identify who God's select are by how their lives are going. Are you respected,
wealthy, have a hot wife? God must approve of
whatever you are doing. The Calvinists built Calvin Towns- Communites for those approved by God. In Calvin Town, people were expected to live "moral" lives, but be wary against immorality within. Surveillance and punishment were part of the social fabric. But this worked differently among different social classes- The lower classes sought to exclude outsiders for being immoral (and poverty is seen as immoral) but the wealthy were treated like nothing they did could have been immoral, because God rewarded them with wealth.
So we arrive at this theological framework where being poor makes you suspicious, and the lower rungs of society are constantly pushing each other off the bottom rung. The wealthy are never suspicious, no matter what they did to get their wealth. Slavery, fraud, racketeering, sexual crimes, founding a genocidal colony overseas- Doesn't matter how many bodies you rack up. Your wealth justifies it. It's an ideological basis for the two-tiered justice system dividing the working class and the capitalist class.
This behavior is taught to the children of the wealthy. The sense of superiority, the dehumanization of the poor. Poor kids go to public school and get taught they need to work hard and sacrifice and obey the bosses. Rich kids go to private boarding schools where everyone believes they are superior by birth, and they are destined to rule over their servants, and if they want resources or a woman they get to take it. If they ever get into serious trouble they are given powerful lawyers to protect them.
What about outside of Western Societies? I think hierarchy and privilege tends to create a similar effect. Outside Calvinism there are other examples: the Divine Right of Kings, the Heavenly Mandate, or authoritarian loyalty to rules, and laws, and social order like under Confucianism. Children are warped by the ideologies of the privileged, and the most warped people seek to exploit others to reach that level of privilege.
The fantasy of stories like this is that the MC is a just observer who is powerful enough to resist tyranny, while most of us have no such power. The rule of law bends for the tyrants and punishes the masses.