Where to begin?
Well, let's start with DRM. People don't appreciate having crippled software shoved down their throats. CDs were awesome because you could share your favorite band with a friend without lending them your entire music collection. Also I don't feel that it's an exaggeration to say that DRM has driven a lot of people to piracy that ordinarily wouldn't, just so they could have some control over their music collection.
Let's continue by saying this is all just a little bit alarmist, isn't it? The reason fewer people are buying iPods is because pretty much everybody in the universe already has some kind of device (like a cellphone) that can play music.
Maybe they should focus more on developing nations - get those kids to hock their OLPC laptops for an iPod, it's a whole new market segment!