Why do people in Higurashi die?

Most explicitly seen in Wataganashi and Meakashi-hen (basically the first season of HnNKN), everyone dies because Shion killed everyone, blaming them for the disappearance of Satoshi

CLARIFICATION!! Shion is the one who kills everyone in Meakashi and Wataganashi-hen. She went around replicating Mion in order to make it easier for her not to get caught, while Mion, who was being Shion at the time, was in the underground cellar of the Sonozaki estate inside of the cage/dungeon. (And no; i am not talking about their switch at birth. The Mion that killed everyone in Meakashi and Wataganshi-hen was SHION, who was really born as MION. But since she does not have the oni tattoo,the majority of us call her by her screen name--the majority of the time she is on screen--SHION)

If this is confusing, or if anyone objects, please shoot me a PM, and I will more than happily explain :)