I've written about it a number of times before, Apple has taken a design and product strategy that is alienating and abandoning many of their most passionate users. In Apple’s iTunes Is Alienating Its Most Music-Obsessed Users, Jesse Jarnow explores how iTunes has evolved into a platform that sucks for people with giant music libraries. Earlier this year, I'd come across an article with related complaints held by classical music fans.
Essentially, all of the crap that they've added into iTunes, plus this overwhelming requirement for iTunes to phone home to Apple, really sucks if you've built a music library. In that way, the core functionality of iTunes has been superseded by stuff that doesn't really relate to music library at all.
If you think about that on an abstract level, this product that used to cater to a very specific set of requirements -- typically the most demanding, passionate users of an application -- has evolved into a giant business engine shaped around promoting selling you crap that they want to sell you. This is less aligned with Steve Jobs, the guy that took days and weeks to decide on the right washing machine, and more aligned with the fluff and seasonality of the fashion industry.