[_hardwaregeek]

Two headphone jacks is precisely the sort of feature that a developer would find handy but might not make sense from a product view. For one, people will immediately wonder, which jack should I use? Are they different in some way? Or worse, if you put the jacks side by side, they might wonder if you need a specific jack style, like airplanes.

It's also less pretty. More jacks is more ports is less sleek. I know, dumb, but the whole point of the iPod was that it was a beautiful, intuitive MP3 player.

Preloaded music is also less sleek, less luxury. While Apple did eventually start providing preloaded music, it was kinda controversial, and at least for me, ended up just sitting on my iPhone taking up space. I also suspect the lack of music might have been a forcing function to onboard you to iTunes as soon as possible.

[outside1234]

Two jacks also would have made it bigger.

If anything, it would have made more sense to have a branch jack in the iPod headphones.