Of course, people who abuse innocents are perhaps the worse humans in the world, but there is another class of people who are perhaps universally hated. These are the liars,
the betrayers , the cowards, the backstabbers, the Snitches.
We probably all had our first encounter with these miscreants in school. Most classes would have the class snitch or tattletale who would go behind your back and tell the teacher what everyone did. Most of us know the story of Abel and Cain, and that Cain killed Abel based on jealousy, hid the body, and all but lied about murdering his brother.
We will note the lying tend of betrayers as this goes along.
In the “joint”, perhaps the worst thing (and most dangerous thing) you can do, is “rat” or inform on a fellow inmate. The phrase is “snitches get stitches”.
You see, betrayers, back stabbers, liars, informants, all have something in common, they
are without honor, without integrity, cannot be trusted, and are liars.
When you think about some of the most hated of people, we think of Benedict Arnold,
we think of Judas Iscariot, we think of Ephialtes of Trachis , the Greek who betrayed the Spartans and told Xerxes about the secret goat path that allowed Xerxe’s soldiers to attack the Spartans from the side. In fact, the worst insult one Greek can give another is to call him Ephialtes.
The qualities of the betrayer are universally hated. If someone presents themselves as a friend who can be trusted, and is all the time, planning to betray you to your enemies, they are beneath contempt. And, because they are false with their assurance they can be trusted, and that they are your friend, they tend to be liars as well. Confidential informants will often claim someone else did a crime in order to get money or get out from under some charge.
Being a traitor, in the armed forces of the USA, is a crime punishable by death. It is because we, as honorable people, have nothing but disgust, even hatred, for those who betray their friends, their country. They are the lowest of the low.
Someone who has no loyalty, and goes as far as to actually betray someone who had trusted them, does not deserve to be able to be associating with honorable people. They deserve to be marginalized, cast out, banished, so that they cannot betray their own group any more.