Apple, by comparison, designs and builds products with a very distinct vision of what a product will do and how its customers will want to engage with it. This works well for hardware, just as it did for pre-Internet software. But it doesn’t serve to capture the unexpected or mundane behavior of people on the Internet, and it certainly doesn’t allow the company to learn or adapt as quickly as others.
Not only iTunes, but all first-party apps in general. Calendar, notes, mail, camera, photos, etc – a couple incremental improvements per year and a refresh with each X.0 iOS release feels archaic at this point. As far as I've heard, there is a very small team of designers that works on first-party apps, so this makes sense from a bandwidth perspective. But it's an underinvestment, nonetheless.