Corporations have legal person-hood; I would think they would act in their best interests. Since a well-run corporation will outlive any of its constituent members, it would seem to follow that they would do something to ensure their continued existence.

I see that as the root of the problem. Legal person-hood aside, the corporation itself has no true advocate. The corporation can easily outlive its Board of Directors and its investors. Selfish¹ people alive today don't really care what happens to their corporations in 100 years, much less what happens to the planet. These people are parasites, taking their profits, killing the host corporation, and moving on to do it again.

I'm really despising corporations more and more. I just don't see how these things can be fixed.

¹not in the Rand sense