I do, one of my best friends. I am also a mental health nurse and have worked with many people who have the diagnosis. She certainly can be reasoned with. She is intelligent, insightful, empathic, thoughtful and considerate.
Her mental illness (I do believe it is an illness, folkgirl) has blighted her life and made life very difficult for her family and close friends. But she is the one who has suffered the most.
BPD has considerable overlap with both PTSD and Attachment disorders and is strongly correlated with childhood trauma. Childhood experiences do affect the physical development of the brain. But our brains are plastic and although more difficult in adulthood, we are capable of re-learning and building alternative neural pathways. Or in more behavioural terms, learning different coping strategies.
Like any illness, BPD will affect people in different ways. There is a specturm and also severity can fluctuate. It is a complicated condition as it often co-exists with other mental health issues such as depression, PTSD and Eating Disorders. The impact of these is hard to separate from the BPD.
The issue of Mental Health professionals refusing to work with people who have this diagnosis - there is a grain of truth in it but it is also the case that this diagnosis has been over-used and applied to people who dare to challenge mental health professionals or who fail to agree with them. It has also historically been used as an excuse not to take people seriously or to treat them with respect. I would hope that is changing in current practice but this remains a very misunderstood illness. The book you quote, OP, I have read but find it one dimensional and damaging.