You're correct that he complained about that, but the point was supposed to be about the exploitation and abuse of laborers.

That's true, but "exploitation and abuse of laborers" and "tubercular beef" were ultimately caused by the same thing.

Upton Sinclair’s complaint was that everyone cared about the health implications but didn’t care about the workers.

https://en.wikipedia.org/wiki/The_Jungle#Reception

Yes. And people sought to address the specific causes of tubercular beef while leaving the rest untouched because they weren't cared about the exploitation and abuse of laborers as much as their own health.

I mean the same thing happened to Orwell. He was a democratic socialist who literally went to war with the fascists in Spain but people think Animal Farm is meant to be a rebuke of communism generally (and not Stalinism specifically).

Well, the point of the jungle is that we need to form a socialist worker's state. Instead, everyone freaked out about sausages.

He had a quote along the lines of "I aimed for the heart and hit the stomach"

edit: > "I aimed for the public's heart," Sinclair later wrote, "and by accident hit it in the stomach."

That point being, to promote socialism.