These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Accidental Aesop: The book was intended to highlight the poor treatment of workers in packing plants, but the descriptions of what was going into the nation's food were so disgusting as to cause the passing of the Pure Food and Drug Act.
"I aimed at the public's heart, and by accident I hit it in the stomach."
Anvilicious: The book pulls no punches in its condemnation of capitalism.
Jerkass Woobie: Jurgis. He would've been a completely sympathetic character, had he not purposely beats up his wife's boss, which lands him in trouble in the first place.
Nausea Fuel: The descriptions of what was going into the nation's food. Dead rats and injured workers aren't most people's idea of savory.
The book states that some of the stuff that went into the meat vats was so bad, it made dead rat look like a trifle in comparison.
Nightmare Fuel: President Theodore Roosevelt actually read the book and sent two guys to check up on meatpacking factories to see how much of the book was accurate. Save for the "human lard" scene, he was told that pretty much the entire thing was accurate. You can resume vomiting now.
Little Stanislovas falls asleep in the factory, is locked in, and overnight is eaten alive by rats.
Some Anvils Need to Be Dropped: The whole reason Upton Sinclair wrote this book. He meant to expose the horrors that workers had to go through because the businessmen and the capitalists had power over them and they were abusing it. However, people were more preoccupied by the fact that EW! someone's finger might have been ground up in their food!
What an Idiot: Jurgis knew his family needed his income to survive and knew that beating up Ona's boss would land him in jail for a good long while. But he did it anyway. If he hadn't done that, he wouldn't have set off the chain of tragedies which he so bemoans later in the book.