I don't have an iPod, and I don't use CDs anymore. I suppose it could have been MP3, BitTorrent and cheap external HDs that killed CD binders, not iPods per se.
I like music, just not when I am traveling outside. But granted, I don't commute much. I tend to bicycle, where iPods would be hazardous. Also, I don't want to blank out my environment.
I listen to a lot of music at home.
As I said, I can understand if somebody has to commute a lot.
Except maybe for some commuters on the train. But I don't think most buyers were commuters.