A corporation is made of people, but its ethos is the product of decision-making. If a corporation is consistently, say, unethical, is it because they hire only unethical individuals? Or because unethical people somewhere along the chain of command make unethical decisions?

I'm not exactly sure what you're getting at with this question. It seems to still conflate corporate-level decisions with boots-on-the-ground work.

Are you suggesting that whatever decisions their upper-level management makes that you consider unethical irreversibly and irrevocably taints all the difficult and honorable work that their engineers and operations people are performing?