> "They didn't seek out a reason to be angry"

A lot of people really do, and it predates any sort of media too. When they don't have outrage media they form gossip networks so they can tell each other embellished stories about mundane matters to be outraged and scandalized about.

> When they don't have outrage media they form gossip networks so they can tell each other embellished stories about mundane matters to be outraged and scandalized about.

But again in this situation the goal is not to be angry.

This sort of behaviour emerges as a consequence of unhealthy group dynamics (and to a lesser extent, plain boredom). By gossiping, a person expresses understanding of, and reinforces, their in-group’s values. This maintains their position in the in-group. By embellishing, the person attempts to actually increase their status within the group by being the holder of some “secret truth” which they feel makes them important, and therefore more essential, and therefore more secure in their position. The goal is not anger. The goal is security.

The emotion of anger is a high-intensity fear. So what you are perceiving as “seeking out a reason to be angry” is actually a hypervigilant scanning for threats.