Hi zippe,
Do they really think "you" (NonBPD) are the problem or are they just making them self feel better by blaming. I feel like my wife is convinced I am the only problem in her life. Is this consciously or subconsciously in BPDs?
there are plenty of people also on this side of the fence that see the problems primarily on the other side. When the relationship becomes distressed it will be true for both parties that on the other side there are a low of issues and both sides are factually right. Another truth however is that one is way more effective cleaning on the own side than trying to direct the neighbor.
Having said this there is a kernel of insight in your question "Is this consciously or subconsciously in BPDs?". People with BPD struggle to regulate their own emotions. As a result they are projecting a lot of emotions on others as part of their own coping. Projection often involves distortions and so it is not unusual for a pwBPD to have a very emotionally colored view of their surroundings.
At the moment your relationship is distressed and she is upset, angry... . . And so something must cause it and what is close and convenient to blame is you.
There is little you can achieve by directly confronting these distortions. What works however is validation which decreases the pressure to distort. What also helps are boundaries which make it harder to project. I would encourage you to pick one of the two skills, focus on it, work through the corresponding workshops, discuss it here and apply it more and more confidently in your life. It won't fix her but it will help you and will help her indirectly too.