You seem to be implying that no anger is justified. If that is true then anger has no purpose, which is rubbish. Of course anger at being treated unfairly is justified. It provokes us to right the wrong. The problem is that most people have been talked out of their feelings by their parents, who were protecting themselves from criticism. They turn the child's anger inwards, so it goes awry. It turns into chronic resentment because the time for action has passed yet the pain never goes away. It gets projected onto symbolic targets (see the comment above).