Human beings' structure consists of beliefs about themselves (as individuals). One of those beliefs usually is that they are a decent person. In order to get by, we must make profit - for example buy a product and then sell it for more. i.e. "Buy low, sell high." However, we just basically ripped off the person we sold high to. We did him an injustice. Not something a decent person generally does. Decent people don't rip off other people. So how do we justify this reality. If we decide the person we ripped of is somehow bad, or at least worse than us, then they "deserve" to be ripped off. That is how the disdain down the supply chain grows.
The nature of profit forces the hatred into existence by necessitating the justification for deriving profit from another individual.
If you answer via stating that profit is a base assumption of the system and therefore not a negative needing justification - that just transfers the injustice to the system as a whole and participation is the source of the needed justification - which again results in the devaluing of other persons and the ultimate development of hatred.