Could it be that there is indeed a genetic lineage that is literally and fundamentally evil?
If the KJV reflects real people and real events, then there is a significant clue there. Lamech (not Noah’s father, but the other one 5 generations descended from Cain) killed a young man (Gen 4):
23 And Lamech said unto his wives, Adah and Zillah, Hear my voice; ye wives of Lamech, hearken unto my speech: for I have slain a man to my wounding, and a young man to my hurt.
24 If Cain shall be avenged sevenfold, truly Lamech seventy and sevenfold.
One could wonder what would make the murder committed by Lamech more than 10 times worse than the one committed by his great-great-great grandfather Cain, five generations earlier. There are answers, but this is not the forum for that discussion. What can be considered just from the above however, is that there is a lineage in which evil inherently (genetically?) exists. And there was something profoundly more evil concerning the murder Lamech committed in comparison to the murder of Abel 5 generations previously. Add to that the existence of other significant evidence that Cain’s lineage (which included Lamech) survived the flood through Ham’s wife. It’s a long, involved story, but if true, clearly points to a lineage surviving today that is very fundamentally evil. They do not think like us, because they are motivated and influenced by a different source that we fortunately can not really comprehend.
Buying into that story or not, the history of the world certainly does suggest that there are people on this earth that are indeed fundamentally evil. And they exist in all parts of the world. There is no negotiating with them.