Here is one reason why ghosting is such a terrible thing to do.
It usually leads the victim to dive into his (often her) deepest insecurities.
As in, where was I at fault? What did I do wrong? Was it Incident X, Y, Z.
You're inflicting the equivalent of a Communist 'self criticism/struggle session on yourself.
Imagine a the victim of a Landmark trained 'ghoster' doing this to herself.
The victim claws herself raw and bloody. What an opportunity if the Landmarkian
returns to her life. She's already a wreck, all he has to do is exploit it.