Bob realizes that human sympathies have limits, and should get over himself
The Chick encourages the protagonist to let go of the already done horrific past and savor their current moment.
Discussed: "You know, maybe it's time you stopped moping about this and moved on..."
Conversed: "Characters who spend all their time moping really irritate me. I don't like to spend time with people like that in real life; why does this author think I want to read it?"
Bob's excessive self-pity and refusal to engage with his past and trauma in favour of lengthy self-indulgent brooding and complaining eventually drives away anyone who initially cared, resulting in the character ending up alone and even more miserable.
Bob starts brooding about how alone and miserable they are instead.
But even the smallest things can have a negative impact in their lives and that Bob seriously is unable to help himself, so a group of not-unsympathetic characters who actually can't find any way to feel irritated with help Bob deal with his problems.
But when an appropriately traumatic event occurs, this has caused Bob to end his angsty attitude, and when others realize that he didn't care about the tragedy, they all wished that he was a whiner again.
Plotted A Good Waste: Bob is intentionally made overly angsty in order to deliberately make him unsympathetic, by indicating that he refuses to deal with his problems in favour of whining about them.