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
Alright, if they're having a romp in the afterlife in some capacity, they aren't ghosts. There's a kind of underlying implication they're sticking around for some worldly purpose or reason. Often this is used for metaphor about moving on in your life (or rather afterlife).