The thing about that author- Joseph Burgo (I've read a lot of his work and read his blog regularly)- when he uses the word 'narcissist', he's not necessarily referring to a condition that would qualify for a full on NPD diagnosis (which doesn't exist anymore anyway with the latest DSM, I believe). I can't find the exact link right now (in which he gives a full definition of what he means by 'narcissist')- but basically, to him, narcissism is a coping mechanism for people who can't handle feeling shame. It's like being in denial, needing to posit 'inferiority' in other people to feel relief from the fear that we are inferior ourselves- and being so preoccupied with that fear that it blocks our empathy, we don't care we are making someone else feel bad in order to feel better ourselves. And I agree that it's at the core of bullying.
But there are times when it seems to me that Burgo has appropriated these terms to explain things in a way that's rather inconvenient- because many people already have a working definition in their head (of 'narcissism' and 'shame') that don't especially coincide with the way he uses them. [So in that sense, I can see your point....if your own working definition of 'narcissism' clashes with the specific way he's using it.]
eta: According to Burgo, narcissism (as a coping mechanism) is the result of early emotional abuse, so this coincides somewhat with what you said instead contradicting it.