The real reason iPods don’t support Ogg Vorbis. →
https://marco.org/2007/04/10/the-real-reason-ipods-dont-support-ogg-vorbis
I wrote about this a while ago in Should the iPod support Ogg?, but Daring Fireball points out an entirely new reason (as if Apple needed another): Ogg probably violates some MP3 patents, or comes close enough to ensure a painful and expensive court battle, and no big company wants to put themselves at risk by officially supporting it in their high-profile products.