How can one just be written off like this?
It's a defense mechanism, a way to deal with emotions she can't deal with otherwise. We all do that to some extent, change what things mean to us to feel better, but for borderlines, folks with intense emotions they can't regulate well or at all, extreme measures are called for. That's standard borderline, apply as needed.
This is so true. This is a core feature, this is perhaps the dominant feature. The splitting / devaluing.
I asked a similar question of my T, though I chose to take the road to divorce. When I asked him how my dBPDxw (after I'd announced an intention to divorce) could say things like "I never felt anything for you" -- and this after me working diligently in MC to save the marriage -- he told me that there really is no way to understand it, because in doing so I'd be trying to wrap rationality around a thing that is as irrational as it gets.
People with genuine BPD, and I suspect those with pronounced BPD or NPD traits, are not rational adults with a conscience. They are more like children in adult bodies, and petulant children at that. My abiding impression of the breakup of our marriage is that she was "caught" in an adult relationship, where she had no right or ability to be, she'd always known this, and I'd finally detected it.
So while the poster's situation is terrible, I think that it is all too common. Get ready for fireworks when she realizes that she'll be living in a basement apartment on the rough side of town once the divorce is complete.
