When corporations knowingly kill people it isn't careless. What they do is entirely calculated. For example, it wasn't carelessness that caused the Philip Morris executives to hire a bunch of scientists who were then ordered to falsify reports saying that smoking wasn't harmful in an attempt to trick the public to keep smoking when the company was sitting on a mountain of evidence showing that their product was killing people.
Government violence is different though. When the government acts against the public they are generally required to follow long and complex procedures with multiple points of checks and accountability. A cop has to get enough evidence to convince a judge to issue an arrest warrant. A person is taken into custody and given access to a lawyer. A trial is held in court with a jury. At every step there are volumes of records detailing exactly what was done, by whom, and why. All of that information is public record and we can request those records to keep watch on what the government does. If the government abuses the power we give them we can vote them out of office and replace them.
Obviously there are a lot of problems with our legal system and places where all of that breaks down, but the goal was for there to be transparency and accountability and nothing stops us from improving the situation. With corporations on the other hand, they act in secret, they don't have to ask anyone for permission, they aren't required to keep records of everything they do, you have no legal right to examine the records they have, and even if you find out a CEO is responsible for murdering a bunch of people for profit you have no power to vote that CEO out of office.
It's pretty clear which of whose two entities is the larger threat. Which one of them has already repeatedly poisoned you and your entire family. Which one do you think was responsible for more violence done to your loved ones?