The outrage over American Psycho was absurd, although given our warped and hypocritical society it was hardly surprising. Far bloodier stories had been eaten up by Americans long before American Psycho was published in 1991. The Texas Chain Saw Massacre, which invented the genre of slasher movies, was released in 1974 to be followed by countless sequels and copycat movies. People love to watch bloody, murdering psychopaths.
Why did Hollywood produce so many bloody slasher movies? Take a look at these numbers. According to the International Movie Data Base: The Texas Chain Saw Massacre cost $83,532 to make and grossed $30,859,000 in the US alone. And remember, this was in the early 1970s, when it cost maybe two dollars to see a first run movie. And a movie like this would not have played in the nicer theaters so admission was probably one dollar. (Your servant was a college student in those days although I never saw the movie because it seemed so moronic.)
Subsequent rental income for The Texas Chain Saw Massacre once videos were invented was $14,221,000. Added to the gross from theater revenue, this is a return on investment exceeding 500%. To paraphrase PT Barnum:
…no one ever went broke presenting stories of blood and gore to the American people.