Well, the main thing is that a lot of people report being very badly traumatized by people who have Borderline Personality Disorder and leave them feeling that there may be an outburst of extreme anger at any moment for any or no apparent reason, which has damaged a lot of people growing up and living through knowing people or having family members or parents or relationships and spouses with this disorder. I don't think anyone cares about what I say luckily, so I think my ramblings or rants or whatever probably do less damage psychologically than a person yelling in your face and pulling out a knife and saying they are going to jab it into something in the next few seconds and other insane stuff I've heard from people who lived through crazed BPD outbursts (maybe your friend doesn't have it that bad, but its left a lot of people feeling very messed up and afraid for the rest of their lives, so I wouldn't take it lightly and the stigma doesn't really come from nowhere, but does come from lots and lots of stories of dealing with people with severe reactions who have or seem to have BPD or some kind of extreme issues with anger and violence and taking offense and difficulty controlling their outbursts and rages and even violence).