I think a lot of it is image management. Like new potential partners (probably partners that were betrayed by their own spouses ) are gonna ask them about their divorce and anyone with half a brain knows that they will look better if they can answer that they are friendly with their ex. Or give them a line like “well we realized we make great friends but lousy spouses”. It probably saves them face to family and neighbors or peers.
I think another part of it is that they lack empathy and are just so entitled that they can’t even see how what they did was wrong. Plus, they probably lie to themselves. . The things my ex said during and was just so unreasonable and completely inaccurate and crazy. It’s cause they can’t actually face that they did things that bad. To own up to that takes a lot and I don’t think many are capable of that type of self reflection. Or they wouldn’t have done what they did.
The problem is that the way most of them left was abusive. Cheating, betrayal, lies. To act all buddy buddy, normalizes abuse. It normalizes their bad behavior.
When my ex first left, him and his mom thought we were all gonna have family holidays and birthday parties together. I’m so glad, my family talked sense into me. Cause I was thinking these thoughts like “I need to be friends first” and “I need to act as if” I’m order to get him back. God. That was so pathetic. I will never be friends with my ex. He is a bad human being to have done what he did.