i just feel bad for whoever is in your life that has it and you couldn’t care less.

Not to completely generalize from there, but "the person in my life who has it" has wreaked havoc on the life of nearly everyone she ever came into contact with, tried to sabotage my relationships to other people out of jealousy by blatant invention of her own facts and manipulating, and just in general had a noticeable negative impact on my life and other people who were close to me. And she wasn't even a family member or a partner to me; those are the people that tend to be in for hell.

To be blunt, I don't give half a shit about her for those reasons, because she clearly just uses the rest of the world as a playground for her emotional dysfunction, and she doesn't give a shit about anyone else. As far as I'm concerned, she's basically a narcissist with emotional regulation problems. I'm not saying everyone with the diagnosis is like her, and where I generalize, I generalize with the implicit understanding that that stuff is "on average" and not necessarily "universally". For the empathy thing, there are various studies you can look into; the projection thing is result of the inability to properly mentalize (understand other people's emotional states -- again, can find studies that find this is generally impaired in people with BPD).