This is just naive. Every company that makes any kind of product has made some kind of trade like this.
Costco sells you knives cheaply because they will not be liable if you murder people with them. If the Costco investors were liable for murder every time one of their knives was used to kill someone, you can bet they would just not sell them entirely.
Just because a company thinks about liability doesn’t mean it’s immoral. Individuals avoid liability as much as possible too (see insurance).
I'm not sure what your point is. My comment is a statement that corporations do have a responsibility to act in the interests of society, not an analysis of the particular ethics of selling knives or avoiding liability.
Corporations should only exist because they are net beneficial to the public!
I do agree that enough companies are unethical that it is reasonable to expect it.