I would have no reason to tell someone my mental health diagnosis, just as I would have no reason to tell someone my medical diagnoses.
Others think I make horrible choices in life, or that for whatever reason I don't have anything to show for myself, but that's about them and their not being comfortable with me. And frankly, I have enough to do taking care of me. I don't explain, don't make excuses, don't say BPD made me do it; I try not to let others lay guilt on me or be passive aggressive toward me. Most of my intense suffering is internal and mostly only noticable to me. Maybe I'm lucky that way, I don't know...