Everyone knows that, it isn't insightful at all.
What surprises people with these stories is how people let the situations escalate and don't stop to think, "hey wait a minute... Its just kool-aid". In 99.99 percent of conversations about proper look-aid preparation (haha) that escalate to heated arguments, one or more of the individuals will deescalate or diffuse the situation before it turns violent. So it is surprising, tragic, and in this case almost humorous (though still terrible) that a conversation about kool-aid turned into a gun fight.
Obviously people can be violent and aggressive over anything, even if someone looks at them the "wrong way".