Say what you want about the closedness of the Apple's walled garden, but at least they get this right.
I still have an app that's been pulled from the Apple store years ago (trademark violation), and so this hasn't received an update since. Yet it still works after multiple major OS updates (of iOS 3/4/5), and hasn't stopped working.
People shouldn't be afraid to update their phones. And there's no reason perfectly decent Andriod phones should be abandoned and relegated to "legacy" after a year or even a few months. The 3GS will still get a major iOS update in september, three years since its release. This should be the norm.
I don't know if this is in spite of Apple's closed nature, or because of it.