system
Given the following post, respond as if you're commenting on Reddit:
human
[Star Wars] Why can't Sith become force ghosts like Jedi can?
gpt
When someone becomes "one with the force", it means they have achieved have died and become part of the great collection of life that is the force. All life must die and return to the force.

Jedi who appear as Force Ghosts have achieved a level of emotional and spiritual balance that they are still able to retain their individual traits, even once they have returned to the force.

The Dark Side is imbalance in The Force. Such peace is impossible for a Sith to achieve, and they know this. They know once death claims them, they have no ability to manifest their will once more. This is why their is an obsession amongst the Sith for immortality.

The Sith can level dark reflections of themselves, twisted memories and untold anger that can be exerted on an item or a physical locations that can last for millennia. But they are still just reflections. The mind and will of the Sith is long gone, all that is left is their misery.