How come no one else could hurt Moira by hurting themselves other than the main guy?
When he was down in the cellar wishing they were all dead...did that create some kind of bond between him and Moira? Because no one else could hurt her physically other than him? Why?
I don't think it's so much that Lincoln created a bond between him and Moira. I think that Lincoln's expression of his anger and pain "awakened" the very same emotions and feelings that other characters had buried for so long: Guilt and anger.
Once Lincoln began to act out on his anger/deal with his guilt of the others' being harmed, it triggered other people's emotions and memories to recall similar experiences they had in their life previously. Because Lincoln was the one who mainly influenced others to begin acting such a way, it was his death that ended Moira's "haunting".
I personally think Moira might have entirely been a metaphor for the audience to decipher, but that's another conversation.