Death

Death is what happens when organisms cease natural function and begin to decompose. In the JTK and Slender-verses however, it's what happens when an edgy emo stubs their toe on a candy wrapper and decides to let out their angst in a psychologist-free way.

THE PROCESS OF DEATH
In reality, death can be brought by many things, disease, age, inadequacies within a species to survive in it's environment, etc. It is a natural process that happens to pretty much everything we recognise as living. In the damp meat stored in the suethor's mind however, death is a very spooky shock horror tool that will make even emotionally dead people shit themselves.

So, naturally, lacking a basic sense of horror, these authors put as much over the top death in as possible, thinking it makes their story scary and their reader fear the sue. Which it doesn't.

Death apparently also never happens to someone unless they're caught by the idiot who went psycho after a bad hair day, considering that around 95% of all signature injuries would kill the person in, at most, about a week.