Apple gathers data for some of the same reason Google does. Improving services (email, calendar, etc.) is one of them. Some services require data to function, e.g. Siri and Maps and Find my iPhone can't work without location data etc. Some services such as iTunes Genius will, when you ask it to, search your music library and make suggestion on purchases. But it has to do this every time. The difference between Apple and Google is that Google benefits greatly from building a profile of you based on your passive usage of all their service. Apple does not. Google is freaking creepy. There is a software switch in the privacy section of my iOS that turns of "ad tracking" and allows me to control what apps have access to what services. Google tracks everything you do on your phone and you can't turn it off. They when you're sleeping, they know when you're awake. They know when you've been good or bad so be good for goodness sake.

You wrote,"I hate iTunes, and Apple kind of forces that one on you." I assume you mean iTunes on the Mac. I have't used iTunes in months. Last time it was to stream some music to my home stereo. If you are using iTunes to manage you iPhone and iPad then you are doing it wrong. 🙂 I know people who own iPads and iPhones and don't have a computer.