Why is it in popular imagining, that ghosts are {MOSTLY} depicted as miserable lonely sad folks that are stuck to the places they've died in?

Can't they discover the world beyond? Weren't they humans; don't they have the mind to move on and focus on something else, since trauma and grief will run its course, sooner or later, and not just haunt the living?

If I were a ghost, I'd be tired of acting like one... even if I was murdered or otherwise died untimely

With the exception of Casper the Ghost, I don't think I've seen the alternative take on it

This presupposes ghosts do exist, though I believe ye skeptics would tell me no, which, alright, you win the argument