I was once told by a rather wise (and very successful) man: "If the analysts tell you that the money your company has in the bank is a problem, I can tell you that it is a very good problem to have".
All the purchases that Apple made have been made to become a better Apple, Inc. How would owning Netflix or Twitter (or Adobe or Yahoo) make Apple a better Apple? It wouldn't.
We agree, they wouldn't. Whether it's for better or worse in the end, Apple doesn't behave like other big companies. They are all about growing their own tech and remaining focused on what they do best. The bigger they get and the more money they salt away, the more the pressure grows on management to make the big, traditional moves. Usually this means going after other large companies and pursuing that illusive thing called "synergy" in corporate-speak. Often they up end badly. I'd prefer to see Apple's unique corporate culture play out.