But corporations don't behave like human beingsCorporations don't "behave" at all. What you really mean is that human beings behave differently when they work for corporations:
You keep your job at a corporation by promoting the corporate interest.
That's true, but that by itself doesn't make the behavior immoral. If the corporate interest is best served by making products that people actually want or need, and selling them at a fair price, then keeping your job by promoting the corporate interest is perfectly moral.
If, on the other hand, the corporate interest is best served by something else, then we, as humans, need to revisit the whole issue of corporate governance: what is it that puts corporate interests out of alignment with our interests as human beings and members of society? And you can't just say "get rid of corporations" because corporations are necessary: without them we wouldn't have enough food, wouldn't have houses, wouldn't have cars, wouldn't have computers or the Internet, etc., etc.
None of us can survive purely by our own efforts; we need to be able to specialize and trade, and we need to engage in collective projects that required the coordinated efforts of many people. Corporations are a necessary part of doing that. The fact that the legal powers we give corporations have been abused does not mean all corporations abuse them. And the abuse doesn't happen because corporations magically do things without humans doing things; the abuse happens because some humans use corporations as tools to prey on other humans instead of providing value.