#1 "Right and wrong are determined by culture and society" which is correct. It is a subjective quality. Glad we started this on a good note.
In a culture where goods are communally managed you will only live in a shack if everyone lives in a shack. If there is enough for everyone to live in a house, then everyone lives in a house. I would really like for you people who do not want to accept communal good as a (perhaps subjective) moral imperative to at least stop making idiotic straw man arguments. You have far better ones at your disposal, as you show in the rest of your post.
Legally a business has a duty to generate profit. But a business isn't a person so most of the normal moral brakes aren't there. Specifically the businesses duty can (will?) lead it to *deliberately* exploiting individuals, doing environmental damage that is hazardous to nearby residents, or lobbying for modification of legislation to benefit their fiscal duty at the expense of common good.
You can also argue that monopolization of resources both raw, material, and productive means that collectively businesses actively exclude public participation in providing cheaper goods and services (since they do not include the markup) that benefit more people. You can see this in all the Municipal Wi-Fi projects that are under attack.
In fact it is arguable that businesses or enterprises owned and controlled by a fraction of the population are inherently undemocratic because they control the actual production of goods and services and are actively opposed to the democratization of that production (ie unions of the early 1900s who demanded a lot more than just wages). Meanwhile when the actual democratic state tries to intervene and impose moral/ethical restrictions on businesses they are actively rebuffed and campaigns are made by employees specifically paid to undermine the decisions of a democratic body elected by the people.
I think I've listed some good points. Corporations aren't evil, they're just victims of their legal duty and apathy of a people. But that doesn't mean that the moral/ethical standard they maintain is somehow acceptable.