Well that depends on what your talking about. Fault in an argument? Most arguements both parties are at fault. Unless you were just wrong (you-whoever was wrong). just finding general fault in people those people are scared and not confident in their own abilities the "haters" if you will. When those people learn to look in a mirror and see what they like they will also be able to see the good around them also.
its our nature... animals in the wild do it as well that is why they have fights with-in a pack and a leader for all their packs not just a group and that leader has their respect or is quickly removed.