I actually think it's Apple's commitment to a closed ecosystem. By doing this they remove a large portion of troubleshooting modern day gadgets and computers by making everything Apple's way or the highway.
It's also why I will never go with Apple, I like mucking about too much to have them hold my hand the whole time!
Ultimately all of Apples products interest me the same, they are all the same products that I like from every other manufacturer. (Cell phones, mp3 players, tablets, etc) Apple just keeps intentionally missing key features and then overcharging for them. The quality seems to be comparable with other manufacturers stuff that I would buy at a lesser price point.
That's my only gripe with Apple.
*Edit* Sigh, it was my only gripe until the poster above pointed out the other thing that bothers me. I *have* to be able to work on my own equipment, and that ability is much more difficult, and again costly, with Apple products.