The only people who post there are those who had bad relationships with individuals with BPD, the ones who have healthy and happy relationships will not post there, obviously. Just because some people have bad experiences with others who have untreated BPD doesn’t mean everyone with BPD is guaranteed to behave in the same ways.
If there was a subreddit called r/lefthandedlovedones full of people complaining about bad experiences with left handed people, that doesn’t mean that all left handed people are abusive.
Like I mentioned earlier, I am that someone, both as someone with BPD but also because of the healthy relationship I have with another person with BPD.
However, I see you’re not really going to engage reasonably or in good faith, so I’m not going to argue with you.