It's very much like a daily horoscope. Make your classifications broad enough and people can cram anything into the pigeonholes. You could classify people as having "convex" and "concave" personalities, and the true believers would be able to classify everyone into those categories.

The (Gervais) psycho-clueless-loser model basically says that parasitism as a strategy is as successful in human social interaction as it is in biology, if not more so. The sociopaths rise to the top because the clueless have not evolved a defense mechanism. The losers have evolved the defense mechanism of generating no excess productivity.

None of the models you mention--Gervais, Marx, or Rand--really say anything other than some people are selfish pricks, and that other people react negatively to that. And there really are selfish pricks everywhere you look. Giving them a new name is almost like finding a new species of beetle.

You can join them, support them, or resist them. There are positive and negative consequences for each choice. What you can't do is eradicate them, because being a selfish prick is a choice, and anyone with free will can make that choice at any moment.