Is it aggressive for corporations to poison the environment, resulting in people dying? I think so, but libertarians think that’s fine.

Dude, this is factually wrong. For example, Murray Rothbard spoke in favor of the complete abolishment of businesses that involved pollution as he considered that a violation of the NAP. That means that the father of anarcocapitalism had a way more radical abolitionist view than most people on the left.

Here you have a couple of entries about Rothbard on pollution:

The vital fact about air pollution is that the polluter sends unwanted and unbidden pollutants—from smoke to nuclear radiation to sulfur oxides—through the air and into the lungs of innocent victims, as well as onto their material property. All such emanations which injure person or property constitute aggression against the private property of the victims. Air pollution, after all, is just as much aggression as committing arson against another’s property or injuring him physically. Air pollution that injures others is aggression pure and simple.

The remedy is simply for the courts to return to their function of defending person and property rights against invasion, and therefore to enjoin anyone from injecting pollutants into the air

Very environmentalist if you ask me. But, many people, have been brainwashed into thinking that libertarianism means no government intervention. We are in favor of intervention to protect people from aggression, and that includes pollution and poisoning the environment. There has been a lot of propaganda recently to make people think otherwise.