Food for thought, fanboys.
iTunes is the most successful piece of media consumption software in the world. It forms the core of Apple's ecosystem. Your iPhone, iPod, MacBook and iPad all use iTunes to sync with your media library and much more. iTunes works for burning and ripping CDs, it forms the gateway to a huge media store, acts as a social network and basically coordinates the entertainment lives of its customers.
As John Naughton points out, this is not a good thing. iTunes was originally built to allow people to rip all of their music to one source. Nearly a decade of additions and growth has turned iTunes into a bloated, cobbled-together monstrosity that is increasingly difficult to add onto.
This makes Apple less nimble, less able to alter their strategies to align with the wildly shifting winds of the tech and entertainment industries. Apple thrives because they provide the best user experience, and ease-of-use is a big part of that. The iTunes interface is poorly designed and awkward, filled with rows of folders and tabs and options. It does many things, but all of those things could be done so much better if Apple would roll out a new, modern media hub(s).