I suppose if that's the easiest way to think of us. We certainly are propelled and fueled by the greed of humans.

[There might be more to it, but it was fine to think of him in simple terms so long as he wasn't reduced to nothing more than an annoyance. He was so much more then that after all.]

It's a term for anything harmful to humans, though I feel that it's too overly simplified. If I was to use in that manner, I'm certain that I would be listed among the kaijin as would others of a more inhuman nature.