Accusations and going against each other only causes chaos and doesn't help the situation because everyone wants to be able to have someone to blame for their misery even if it means causing others to suffer.
Welcome to Maple St
First, out of fear from accusations Charlie takes a gun and shoots a shadowy figure that was towards everyone and finds out what he expected to be an inhuman creature, turned out to be his ordinary innocent neighbor, Pete Van Horn. Then, everyone was too busy trying to blame each other to ease their fear, that they didn't solve the problem or find clues as to how it was caused. Last, the aliens state that others do the same as in Maple Street blaming and hurting each other, it's a repeating cycle of people blaming the innocent just to have a "guilty one."