The simplest explanation was that it was kinda cultural DNA.
The mainstream belief Confucism was extremely permissive for abusing of authority: women must obey men, sons must obey fathers, subjects must obey kings without questioning or being branded as disloyal, even if they were order to "just drop dead". While for a long long time, no checks and balances, like codified rules of laws or discentral political system, to reigned in what degree of authorities those superior status were vested upon: now the most superior, the king, even if they were totally rotten, had totally unchecked power, (seriously, if not for fragrant unchecked power, a whole harem with hundred of beauties and no one protested such greed, cruelty and gross?) The only checks available were those slippery "virtues" which only idiots cared and smart ones often used as blunt weapon to cobbled oppositions (given what written on those classics stories); vague "divine punishments" to the "sons of heaven" (eg. floods, droughs, famines) which came decades way too late for cold comfort for their victims.
The conclusion: it was better to be the perpetrators than the victims, and do that at all chances possible, screw ethics!
And the earliest written stories and novels in China, like "Spring and Autumn Annals", "Romance of Three Kingdoms", "Water Margin", ect., were glorifying bloody millitary feats, cunning murder schemes or high-handedness of historical figures as virtuous and herioc. Later stories or novels just followed that literature tradition. So, it was just the usual stuffs for writers and readers soaked in Chinese literature tradition.
