I'd actually like to know why this is, but since we probably won't discover that, we can just provide examples of the entertainment geared towards us freaking us the f*ck out. Here are some examples off the top of my head:
- The episode of the Rugrats where Angelica's parents are thinking of having another child, and Angelica has a dream where she's devoured horribly by her new sibling.
- Rugrats, when Angelica tells a horror story about a child being horrifically eaten by a monster.
- Rugrats again where Chuckie sees the world as if he was never born ala It's a Wonderful Life and everyone's lives are in shambles: his father becomes a schizophrenic mess, surrounded by rotting food and cockroaches, Phil and Lil's parents have their home destroyed by their children, and tommy and his family are starved and enslaved by Angelica, forced to cook her cookies endlessly while she's extremely fat. The creators seemed to have some weird thing with eating-related horror. Seriously, what the f*ck?
- Hey Arnold where they tell the story of the Ghost Bride, a white, ghostly figure in a wedding gown and veil that eventually hacks one of the characters to bits off camera (no idea what the f*ck was up with that, because it actually happened) and was perpetually humming the wedding march. What made this particularly disconcerting (I actually remember crying and being unable to sleep afterward) was that the episode took place at night and being completely white made her stand out against the black mist of the cemetery. She just just looked like she didn't belong, and that combined with her slow movement made her seem... unstoppable? I obviously knew by age 6 or 7 or whatever that ghosts weren't real but the very idea of it was quite disturbing.
- The above episode of Courage the Cowardly Dog, King Ramses' Curse. There's his creepy theme music, his inhuman voice and just... the way he moves. He doesn't move like he has a semi-functioning nervous system the way Romero zombies do, he seems like he doesn't walk, and moves his arms stiffly to express himself, like that is actually what a corpse reanimated with black magic would look like. It still scares the sh*t out of me today. Uncanny Valley, or what? I named the topic after him because I assumed anyone who remembered it would instantly get chills the second they placed that quote.