Originally Posted by
Jinsai
it might have stuck out in the film because it never really established that the tone was that dark... in the book, Pennywise as the entity is tied to cruelty and fear. It goes into phobias and racism. They have segments in the book that go over town-justice mob killings, racial lynchings, and societal failure to protect the innocent... it all ties into what fuels the entity in the book, and the scene you're talking about is crueler in the book. Putting him simply, IT's sort of fed by the town's general awfulness, and acts of supreme intolerance and cruelty are almost like "summoning rituals."
It was a little harder to tell in the film, but the act was carried out by young teens, even if the victims were adults. I'm not sure if that's implied to mean anything, but it's part of the darkness and the deeper meaning of the story that Pennywise thrives off of that sort of thing, maybe is suggested to fuel and empower it. It's upsetting and awful but it should be. Honestly, I thought that was one of the only scenes the film did really well.