THE RIGHT THING IS NEVER EASY
What makes MDZS a great story, and not just a good one, is that WWX is an incredibly moral person, who puts doing the right thing above everything. Societal rules, personal relations, even his own health. This is not him being insecure or not having self-worth. It is him having an incredibly strong moral core, and recognising that sacrifices are often necessary when you want to do the right thing because the right thing is never easy. So, we have the general goal of the protagonist: Stand by what is right.
And why is the right thing not easy? This is where the conflict comes in. In MDZS, the conflict is man vs. society. It is WWX's tenuous position in the high society of the cultivation sects, which by the way, is filled with classist assholes, that lead to him being villainized. MDZS is a story of how society exploits rules and traditions, and turn dark. No one is wholly blameless in the fact. After the war, LXC, NMJ, and JC were all in positions of power to stop the brutality of the Jin Sect.
LXC's sins are more forgivable, perhaps, because LXC does stand up for WQ, and we really don't know the extent to which he and NMJ were aware of the wen remnants only being civilians. However, even when WWX points out very, very relevant points at the banquet, LXC, who leads the sect with the motto, 'Be Righteous' is unswayed, and doesn't pursue the matter.
NMJ, for all his strong sense of justice, clearly has no idea what it is like to live under a tyrannical dictator when he says,
Nie MingJue spoke coldly, “If she responded with only silence and not opposition when the Wen Sect was causing mayhem, it’s the same as indifference. She shouldn’t have been so disillusioned as to hope that she could be treated with respect when the Wen Sect was doing evil and be unwilling to suffer the consequences and pay the price when the Wen Sect was wiped out.”
The crime NMJ accuses WQ of is the same crime he is guilty of. Indifference. The only difference is that WQ actively went against WRH's command to join the battle lines, saved YMJ's heir and ensured its survival. NMJ, on the other hand, not only did not but later on, joined the siege against the innocents.
Again, we don't know how much the Nies and the Lans were aware there were only civilians. We don't know if the Jiangs and the Jins were the ones who carried out the slaughter, while the Lans and Nies fought the fierce corpses there. It is likely they believed there were cultivators and war criminals at the Burial Mounds, But, it is also likely that they had some idea that civilians were there as well.
And JC... well, we have absolute proof of JC's crimes. I have talked about this before, others have talked about it, and the gist of it is this. JC does nothing to pay back the enormous life debt he owes both Wen Ning and Wen Qing. Instead, he condemns them to death. He abandons his sect brother and turns the world against him. He leads a siege against a mountain full of civilians.
The Cultivation Sects would do nothing for the Wens, and this is further emphasised by the fact that even LWJ recognises that WWX has 'no other path'. This is not about MoDao. It is about protecting the Wens.
So, society exploited the ideas of 'righteousness', of 'justice', of 'honour'. During War, they all did awful things. But the absolute horror of what happened to the Wens was that they were brutalised during peace. The horror was that a dictator was removed, and in its place, arose a society that plundered and murdered innocents.
The thing is, we don't know, really, if even WRH was ever this blatantly cruel to civilians. We know he didn't care for their safety or anything - case in point, waterborne abyss, but QishanWen Sect was a vast, vast behemoth. We don't really know how much was his direct orders and how much was idiots like Wen Chao slacking off. We know he slaughtered the entire Jiang Sect, but again, cultivators. We don't know if Wen Ruohan pulled civilians into his power play in the cultivation world. (If there is actual textual evidence against this, please reblog and share. I read the novel quite thoroughly multiple times, but if I missed anything, please let me know.)
So, if the result of the SunShot Campaign was a society that slaughtered innocents, then how could they even call it righteous
So, again, conflict is Man vs. Society. ( In most fix-it fanfics, people remove this conflict, and are left with rather a shell of a fic. I theorize this is where most of the insecure WWX tropes come from -> so conflict becomes, Man vs. Self)
But Karma is an actual, real thing, and we see it happen. WWX, who stood by the right thing, who refused to let society declare cruelty as justice, was reborn, with a body that has a core he can cultivate and is able to live without regrets and live happily, with a man he loves. JGS, who was responsible for the whole thing? Look how he died. LXC's actions in response to JGY's crimes, lead him to being devastated, and goes into seclusion (Note that if a similar investigation was held with respect to the Wens, the tragedy might not have happened) is by far the kindest ending because it shows potential for growth. JGY and NMJ, one slightly better than the other, certainly, are sealed as fierce corpses. JC is faced with total abandonment from the last person from his past, and the realisation that he has no right to compete with WWX, that WWX owes him nothing, which for him is devastating, as we see from how easily JGY uses it to manipulate him. The Jin Sect is surrounded by rumours and general dislike from the cultivation sects (Not you Jin Ling, you're doing lovely, sweetheart.)
That's why MDZS is an absolutely brilliant literary work. It shows that doing the right thing isn't easy, it is a slippery slope and you can fall very easily. But life always rewards those who try, and always punishes those who don't.
