It's funny how retail versus wholesale death is seen so differently.
Kill a few dozen people with your own hands and people are (rightfully) horrified.
Run a business that enables the killing of orders of magnitude more people, and you can be a respected pillar of society.
Killing instantly becomes respectable if it's done legally and for profit.
I suggest you look into the perception of self defense. Saving yourself and others via killing compared to killing to commit a crime are perceived very differently.
That’s not it. There are plenty of industrialists who have killed far more than any serial killer just for profit and they don’t get anything like the opprobrium given to serial killers.