Do I get you right?
Because Apple proposes an aditional way of syncing it's ok to mess with the old way?
I would rather call it design decisions for new, major software releases. Most parts of iOS and macOS have been completely rewritten, new features added to support new media items like Live Photos and 3D photos, a new file system. When an operating system needs a major rewriting, because most of the basic system services have changed, it is natural to start small with a slimmed down version and remove legacy code. This way the operating system will not hog all available storage, will be easier to maintain and develop further, and will be much faster.
The next system iOS 11 will probably break many more features and support for older apps. Since my iPhone has been updated to iOS 10.3.2, many apps I love are telling me, that they need updating and the current version will not run on the next iOS version. There are a total of 22 apps, many of them important to me, like exiftool, where no update is available and that will not run on iOS 11.