The Mutated Humans - like the cannibals, was another species not accepted by humans.
A giant figure, strong muscles, an ugly, twisted face, and grayish green skin. Just like the monsters from <Lord of the Ring>.
The FEV virus in their cell structure had given them an insane regeneration ability. From some perspectives, they could be considered immortals unless they asked for their own death. At the same time, the ferocious FEV also made them immune to any diseases, and free from the risk of radiation. They boast themselves as the "perfect human" and praise that the heaven like wasteland belonged to them.
Of course, the above was was not the reason they were hated. There were plenty of arrogant, ugly people, and with enough radiation dust, the head was bound to become abnormal.
The survivors disdained them because they were di*kless.
Not only that, they liked to capture people, and turn them into the same di*kless creatures they were.