The perception of Apple customers has been that they're typically left of center. Apple haters fired the "your iphone is made in a sweatshop" volley (legitimately, I might add) because of this perception of Apple's customers and an attempt at shaming them. Apple responded by enforcing ever stricter standards of minimum working conditions on all their suppliers, thus safeguarding the customer base. Continuing along the same lines and in service of safeguarding their customer base, Apple started moving towards green energy also because that's yet another selling point to keep their customers hooked. It's also the reason why in every product launch, the greenness of the product is a feature touted alongside its technical merits.
Customers give Apple money in exchange for Apple products. That's how Apple became valuable enough to have so many shareholders. Take away the customers and you're holding a shell. The customers *want* a company that is at least a little altruistic because it makes the customers feel good about themselves.
If shareholders treat Apple like the goose that laid golden eggs, they'll suffer the same fate when they try to distil the company to the essence they (wrongly) perceive it to be.