The reasoning is like running a firewall - you block everything, then open up only the services you need open, and only from the sources you need things accessible to.
By analogy, Apple can make it so that nothing syncs with iTunes, then open it up so that the iPod and iPhone do.
By doing that, they cut off anyone ranting that iTunes is rubbish because it crashed when syncing their music (unmentioned: to a third party device).
Microsoft picked up an incredibly bad rap for bluescreens, enormous numbers of them were caused by poor device drivers and shoddy third party software. Apple has little benefit in allowing El-Cheapo Music System to sync with iTunes, but lots of potential downside (support calls, lowered image of Apple, people migrating away from the Apple ecosystem towards less profitable accessories, buggy integration that requires development and testing of software update workarounds).
By analogy, Apple can make it so that nothing syncs with iTunes, then open it up so that the iPod and iPhone do.
By doing that, they cut off anyone ranting that iTunes is rubbish because it crashed when syncing their music (unmentioned: to a third party device).
Microsoft picked up an incredibly bad rap for bluescreens, enormous numbers of them were caused by poor device drivers and shoddy third party software. Apple has little benefit in allowing El-Cheapo Music System to sync with iTunes, but lots of potential downside (support calls, lowered image of Apple, people migrating away from the Apple ecosystem towards less profitable accessories, buggy integration that requires development and testing of software update workarounds).