Why are file formats important? While it’s unlikely that applications will be wiped off the face of the earth, it might be important for you to ensure that any document created now is readable in the future. If your document is written using an app which saves files in a byzantine proprietary format, you may not be able to recover it in a few years’ time without having access to that same application. Nick Heer
This update to iWork just keeps getting better and better: not only does it remove features for advanced users, it’s also significantly slower and switches to a proprietary file format with no backwards compatibility! This makes it much harder for other apps to handle the files and basically impossible for users to retrieve text inside the files without using iWork. Some have speculated that this change makes it easier to sync files back-and-forth with mobile devices, but that only serves to underline iCloud’s limitations.
For some perspective, the much-hated Microsoft Office made the transition in the opposite direction more than 6 years ago, switching from the closed binary formats (.doc, .xls, etc.) to more readable XML-based files (.docx, .xlsx and so on) in Office 2007.