iTunes also includes drivers for CD burning and a few other bits of functionality.
Plus the iPod has been around much longer than the UMDF so I wouldn't expect them to have rewritten their drivers for it. Neither is UMDF widely available on client computers (it isn't installed on my computer, for example).
Sorry I have to disagree with you on this one. Apple has slowly been adding crap and crap to Itunes+QuickTime + Burn to CD +++++
Why can't it just be iTunes? Why do I have to use quicktime and have quicktime installed in order for iTunes to work?
See Ed Bott's take on this mess for a great opinion