Since forever, stories of human death and destruction of property have intrigued and thrilled the listener and created a massive revenue source for story tellers and a huge movie industry from which 98% of the productions are of human demise. When the computer gaming industry wanted to make great wealth, they turned to the old proven method of DEATH fables and MEN love it. Maybe the reason the Christian bible is so popular is for its fables of mass genocide, commands from a 'god' to kill, all sorts of human misery and promise of "end days" mass death.
While most will argue that movies music and games of death are all just art imitating life, it is a proven fact that there are many people who become what they watch and play because it grew into a fantasy, and that fantasy becomes their reality. However since there is so much wealth made from death imagery, the story industry will just keep the delivery going.
The greatest scourge: Mankind spend a vast amount of Earth's resource to make BETTER WAYS TO KILL HUMANS!
Though there is the periodic serial killer or mass shooter in many societies, primarily in America, man kind's greatest money maker is in the weapon industry. Without wars there can be no profit for weapon producers therefore they MUST take action to CAUSE wars, and that's not at all conspiracy chatter. No person or group would invest massive cash flow into weapon maker biz without KNOWING that there will be orders. Orders will not happen if the bullets are never fired, tanks are not destroyed, bombs are not dropped and $60mil jets are not crashed, and for that to happen, humans must die en-masse, and the rich do not care because they will never see the battle field.