The limitation of apps not saving to the iOS file system is not a bad thing. It is progress.
There is nothing preventing my shiny new iOS app from sharing files with other applications. Apple is just preventing those files from being stored on the device.
Instead, if an app developer wants interoperability, they can have the app save a file to Drop Box, or my Google Drive. Any other application can access that same cloud storage and access the file.
The beauty is we've moved beyond sharing between applications on a single device. Now EVERY application I run on EVERY device I have has the potential to share the same data seamlessly.
This is why iOS doesn't open its file system. It wants the app developers to use something a little more flexible and reliable.
Implementing interoperability with all the possible cloud storage systems shouldn't be left to each app developer separately. This should be a feature of the operating system.
As an Android user, I'm genuinely interested if iOS users find the sharing options between apps too limited. Do you often end up requesting new sharing options from the developers of your favorite apps?
Also, not every piece of data is a file I'd want to save to Dropbox. For example, I share article URLs from Flipboard to 2cloud many times a day (2cloud opens the URL on my desktop browser). I'd hate to have an extra save/open step between the apps.
My argument to this is that having access to the file system just gives developers a cop-out. If you give app devs access to the FS, they will all use that because it's easier and avoids the challenges of supporting cloud storage. However, this is ultimately worse for the user experience in the end.
I get what you mean about only wanting certain documents on Drop Box - that was just a limited example. The spirit of the concept is that the developer can choose what cloud storage to use based on the application.
In the case of a mobile Photoshop app, Drop Box might make sense. In your example, the storage medium would be different (maybe proprietary even) but a cloud space would still be ideal for the end user over just storing these URL's on the local device.
Nice though Dropbox is, I don't have an account on it. You're saying that in order to share data between two apps on the same device, I should have to sign up to a third-party system to do so?
Then, if I have different kinds of documents, I should sign up to a bunch of different third-party cloud systems? Each sign up being another username and password, another point-of-failure for security, more management overhead? All for a system that won't work if I lose network coverage (rural, underground, airplane mode, choked tower, foreign travel etc)?
The cloud does have its good points, but I do not buy this snake oil.
There is nothing preventing my shiny new iOS app from sharing files with other applications. Apple is just preventing those files from being stored on the device. Instead, if an app developer wants interoperability, they can have the app save a file to Drop Box, or my Google Drive. Any other application can access that same cloud storage and access the file.
The beauty is we've moved beyond sharing between applications on a single device. Now EVERY application I run on EVERY device I have has the potential to share the same data seamlessly.
This is why iOS doesn't open its file system. It wants the app developers to use something a little more flexible and reliable.