It's more profitable to operate when there's no expense or regulation associated with negligence and malice.
https://en.wikipedia.org/wiki/Fda#History
https://en.wikipedia.org/wiki/The_Jungle#Federal_response
The Jungle is a 1906 novel written by the American
journalist and novelist Upton Sinclair (1878–1968).
Sinclair wrote the novel to portray the harsh conditions
and exploited lives of immigrants in the United States in
Chicago and similar industrialized cities. Perhaps his
main goal in exposing the meat industry and working
conditions was to advance Socialism in the United
States. However, most readers were more concerned with
his exposure of health violations and unsanitary practices
in the American meatpacking industry during the early 20th
century, greatly contributing to a public outcry which led
to reforms including the Meat Inspection Act.
The book depicts working class poverty, the lack of social
supports, harsh and unpleasant living and working
conditions, and a hopelessness among many workers. These
elements are contrasted with the deeply rooted corruption
of people in power. A review by the writer Jack London
called it "the Uncle Tom's Cabin of wage slavery."