Apple has been successful so far with a very careful strategy: they focus on just a few markets at a time, only enter new markets if they have a big competitive

Apple has been successful so far with a very careful strategy: they focus on just a few markets at a time, only enter new markets if they have a big competitive advantage in those markets and only release new products if those products are a big improvement on the prior status quo. If they were to spread management attention more thinly by starting separate divisions to do the sorts of entirely unrelated things you describe, Apple could easily turn into IBM or Microsoft. At its heart, Apple is a small company. The main way Apple helps all those other industries is by training engineers to think in the Apple way who then go off and found start-ups of their own. And by making lots of millionaires to fund those start-ups. (Apple's also investing in some of those industries as a customer. For instance, they invest in "green energy" by buying solar panels for its new HQ building.)