The worst person I ever had the displeasure to meet (and I'm including people who abused me as a child) was a boss I had at a retail job. [the failings of this mediocre, nasty, creepy, despotic cheap plastic knock-off]Unlike the people who abused me as a child, this person was cruel on purpose and I consider that far worse. He was a racist, sexist, cissexist, ableist, fat-phobic looksist who never showed compassion, had no sense of humor and literally zero good qualities. He talked about the sex he imagined his teenage son having in a way that made it clear to me that the only reason this shitwad wasn't assaulting young girls was that he didn't think he could get away with it. I can only hope that saves people from becoming his victims.
And this dude thought people liked him. He thought his employees were his friends because they laughed at his awful jokes and pretended to take an interest in his alternately brain-scrapingly boring or skin-crawlingly creepy stories. He hated me because 1) I violated his sexist beliefs by existing 2) I didn't allow him to mock me or put me in my place and 3) I did not laugh at his fat-phobia, islamophobia, racism, or other 'jokes' he made.
He deadnamed me and refused to call me by my real name, and told people hired after me that they could also deadname me. (to which I responded, "you can -- I won't answer to it but you can call me that." None of my coworkers were that disrespectful, at least not to my face) Lest you think that he was rude 'to everyone equally,' let me tell you that at least three other people went by a name that was not their birth name and he respected that fine because they were cis (although, the cis girl with a 'boy' name was always called "miss [name]" but I don't think she minded). When I was saving bottle caps for an art project (with all my co-workers aware and setting the caps aside for me), he asked why they were in a cup on the counter and when I explained that I was saving them, took it and threw it away. In full view of everyone, with no explanation; my coworkers privately expressed empathy for me after that blatant meanness (and symbolic violence). He knew that I lived an hour away and he continually gave me 4-hour shifts, even after I requested longer shifts to make the drive worthwhile, and he gave me shifts that ended at 5 so that I would have two hours to drive rather than one. He lived in the same city as I did, and he left every day at 3. He worked with most people's schedules, even the one who left the city for months at a time.
But it wasn't JUST me who was scapegoated. He also mistreated my Persian coworker partly because she was a transfer and he was angry that he didn't get to pick, partly because he wanted to give her shifts to his 'friends' and partly because he's a fucking racist. She reported him to HR and he responded by cutting her hours until she couldn't afford her apartment and had to move. He mistreated my Jewish coworker by continually scheduling her for Saturday morning, which was the one time she had asked not to be scheduled, even though she was fine with working Saturday evenings after sundown (when other people would rather not work). He did this over and over until she quit. He mistreated my black queer coworker by continually logging her as a regular employee when she was a shift manager so that he could cheat her out of a dollar an hour. She'd have to go in and fix it every time, or he'd steal her money. He mistreated another black coworker by continually belittling him and making him prove himself with tests despite the fact that literally no one else had to do these tests.
When I finally quit (after months of that shitwad trying to get me to do it), I felt panic at the thought of work even for months after. It wasn't until I'd been working for an actually supportive boss for a while that I stopped being terrified. To be scared of doing what you need to do in order to live and to have food and shelter is a profound problem. And I know it would have been at least three times as bad if I hadn't had a safety net.
Insecure abusive bosses require a scapegoat/drudge so that they can maintain social capital with the other employees. They pick one person (or maybe two) and give that person all the worst tasks, the things no one else wants to do. They give them fucking awful schedules so that they can give great ones to others. They make every problem into the scapegoat/drudge's fault. I have seen it not only with the unbearable waste of space that called himself my boss, but also with the bosses of my friends. One friend's boss literally gives them three people's jobs worth of work so that everyone else in the office can do nothing but chat with the boss all day.
This is what happens when you put dysempathetic, mediocre non-leaders in positions of authority. They don't care who they hurt, and they don't care or even realize that they're doing a shit job -- until an underling shows them up, and then they take the credit and punish the underling. Mediocre people respond to their inadequacies by lashing out rather than re-evaluating their behavior or trying to learn. If this happens more than once, that poor underling is the permanent scapegoat/drudge.
Unfortunately a lot of us underlings respond to attack from a boss by trying to do an even better job, which shows up the boss more and makes them more prone to attack rather than less. So honestly, it is often the best workers who are made into the scapegoat/drudges. Mediocre bosses want mediocre or even bad workers and they'll drive the good ones away so that they don't look bad in comparison. Capitalism: making mediocrity profitable.