I think that there is a logic behind this. People (like some other intelligent animals) are interested to find out why one of their own kind was injured/killed. If they manage to figure out the cause they might be able to avoid the same fate. So curiosity raises their own survival rate.
But our fairly intelligent brain does also accept fictional examples about people getting killed. The other animals likely lack communication skill to tell accomplish this. The ancient people likely told stories about both true and also fictional violent events to teach their children to survive. So we have several thousands of years of experience about learning by fiction.
So our brains likely have an obsessive urge to be interested about violence. Some might be feeling enough disgust or that they are just scared about violence and they don’t like to see any kind of violence. You can try to fight with your own brain but natural urges usually win.
