I believe that they don't bond from the same "place" that we do - their bond is formed around and from a fantasy, (not from the actually depths of who they are) so although it's quite intense, it's actually quite shallow - not really an "attachment" at all - more like a dependancy.
I agree, which is why people can be discarded... . especially if they quickly attach to someone else.
Yes, their relationships are shallow. My H had a golf-foursome with the same men for YEARS. They went golfing nearly every Saturday. When one of them suddenly died, I asked my H if the guy had a wife and kids, and my H said, "of course he did." When we went to the funeral we learned that the guy had never married and had no kids. How could my H golf with the same guy for YEARS and not know that basic info? How is that even possible.
Oh, and one year he called me while I was visiting my parents and told me that a co-worker of his had committed suicide (gun to the head... . H even mentioned the type of gun and claimed that co-workers told him this info). Later I learn that the guy died of a heart attack... . no gun/no suicide... . at all. H just ASSUMED that the guy killed himself because the guy wasn't very old (about 50). How weird. Who assumes suicide out of nowhere? Wouldn't you ask co-workers, "what was the cause of death?" Why assume suicide? My H went to the funeral and still never found out the truth. I happened to find out the truth a couple of months later from mutual friends. When I asked my H about the discrepency, he just said, "well, I though the killed himself because he was only 50." Weird.
When we (inevitably) cease to remain the fantasy they created in our image, they are perplexed and disappointed that they got it wrong again more than than they are hurt - it's a nuisance, and they MUST go on to keep looking (or else they'll feel the pain they're trying to soothe with the fantasy). We were a drug and reality caused that drug to wear off.
Yes, as long as we're feeding their egos, providing for their needyness, and pleasing them, then we're on a pedestal. But, when they feel that they're being neglected, not complimented, etc, then we're knocked of the pedestal and discarded in a ditch. And, if they can find someone to temporarily listen to their rants, etc, they will latch onto that person.
I know that some of this is very NPD, but I do think that some BPDs have NPD traits. My H sure does.