First, when the only requirement to being hired for a job is that your pee tests clean it should be a dead give away that it's menial work and you are easily replaceable.
Second, the author didn't work for Amazon. He worked for an agency that supplied Amazon with contract/seasonal workers.
Third, if employment at Amazon was the only option to pay rent and buy food it's an indication of issues that go beyond Amazon simply being a shitty employer.
Fourth, from one English major to another, you signed up this. No where in the world are English majors welcomed into the work world with huge salaries and corner offices.