Well said, that is truth well written
Aside from the obvious that workers are not slaves (you have freedom to leave etc), thinking of yourself as a slave is a poisonous attitude to have that will hurt you. Perhaps the best way to explain it is with this quote that illustrates the same point differently, "the most dangerous financial mistake a person can make is to think they are working for someone else." If you're thinking of yourself as a slave, you are thinking of yourself as working for someone else. Your current job can be a stepping stone for you to move your career to where you want to be, to reach your goals in life. Even if you're just working as a janitor, you can still use it to your advantage. Think Harrison Ford working as a carpenter on movie sets putting him in the right situation to get a movie role.
If you think of yourself as a slave, it will make you miserable at work. A better attitude is to think, "I am providing something of value to the company in exchange for something of value in return." That attitude makes you feel more free, because if they stop providing sufficient value, you will know when to leave. It gives you power to ignore TPS reports because you know that's not the value you provide. You will feel so much happier at work if you look at it that way. (The Tao of Programming has some good reading to this point in chapter 7, I strongly suggest checking it out).
And maybe as the main point, some jobs just treat you like a slave, yelling at you, trying to get you to work every weekend, etc. Or maybe you just don't like your career, like the guy in Office Space. Don't let people yell at you. That's the case where you should get another job, or even career. Personally, I like programming, and I enjoy a lot of the challenges at work, so I will stay in this career. But I've found a company that is more interested in getting the job done than in how many hours I work. So I work 30 hours a week. Find something you like, don't put up with slave-driver jobs.