A Look Inside the Human Psyche
Sometimes people try to take advantage of (or pull some BS on) someone. For example, let's say someone (let's call him "Meany") was given some power, or put in a position of authority they weren't ready for. Meany tries to use his newfound power to try to help his friend, by unfairly giving his friend a job. Niw Meany and his friend take advantage of the people under them.
Now a funny thing happens, Meany and his friend begin to actually hate their victims. Not just talking bad about them, but actually disliking and having bad feelings towards them.
And, if their plans go wrong, and they fail in their plans, they will even begin outwardly display their bad feelings toward their intended victims. They'll give them dirty looks, talk about them behind their back, etc..
Now why do they do that? These are people they tried to take advantage of, why hate them? Why treat them so badly?
The reason? Because these people are reminders of their weaknesses, reminders of their own negative aspects, reminders of their own failures.
So they aren't really hating their victims, they're hating themselves. And, since they don't realize that, they will continue to hate themselves by finding and mistreating other potential victims.