A sustainable company maximizes mutually profitable relationships with the natural and human systems with which it does business.
This gets at the business case for me. Businesses need larger systems to operate- indigenous communities, forest floors, city governments, coral reefs, etc. They can either break those systems down and undermine their own long-term viability or find ways to do business which strengthen those systems and their own long-term viability.
The frame of relationship-building is also a powerful one for me. When a business approaches a natural or human system it should listen to it, learn how it operates, and evolve a way to engage it rather than simply seeing it as an exploitable resource.