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
In anglo-Christian culture ghosts were explained away as souls in purgatory, and this led to a Catholic/Protestant split wrt whether they existed or not, because Prots denied the existence of purgatory. They are still religiously problematic really — think about how often the 'ghosts' in American media turn out to be demons in order to keep things in line with scripture.
I personally believe there's something much more terrifying implied in the English folk-tradition though: a spirit bound to the last physical vestiges of their time on earth, going through the motions as what little is left of their mind after the trauma of death unravels completely. They're dead — it's over. They can still do the things they did in life, but it doesn't mean anything anymore.
Obviously there are very powerful resonances here for anyone who has witnessed a person sicken and die.