I think it depends how you felt at the point of lashing out, before the friendships ended or faded away. If it was a BPD thing then you may have felt extremely betrayed, rejected or insulted by a little thing they did (or seemed to do) or maybe suddenly realized that they'd been using you, or appeared to at least, and you got angry about that

That's what often happens with me anyway, and once I've got past that point, often the friendship will end and I really don't want anything to do with them again (sometimes I'll break off contact completely). probably because they remind me of what I felt at that point and how extremely painful and disorientating it was and I don't want to be dragged back there again.

The downside is that sometimes I'll put up with people who are clearly wrong for me for years and years because I know how intense I get if I let any negative thoughts come out so I just numb myself and have put up with the most (sorry to be mean) annoying people imaginable. People who've phoned me day and night looking for someone to talk to and thinking I'm the most passive person alive who is always available. People who just talk about themselves without letting me get a word in or who I don't even want to or feel able to speak to about myself.

That word you used, reciprocity, is sooo important and I'm only realizing it recently. A healthy friendship is a two way street. Some of us maybe didn't benefit from reciprocal parenting and our opinions and needs weren't valued as children so we have to learn about that as adults.