When I entered treatment for alcohol addiction I was dx with BPD. I remember googling it and the feeling of hopelessness.

I cried and cried. A Gp once told me that I need to to help myself because of this dx and turned me away from any help. This was 23yrs ago.

I then left treatment and entered long term psychoanalytic therapy. T didn't hold much value in dx. She certainly didn't have me pegged with BPD..
I feel the original dx set me off on a path to discover what the hell was going on.
So I feel if a dx is used as a jumping off point its OK but if you're just going to be held hostage by it than it serves no purpose.