[joeld42]

There's a standard naming convention, iOS load [e-mail] on retina and image.png on non-retina but it's not strictly enforced so apple couldn't delete all the @2x images on a non-retina device. Plenty of universal apps use the @2x iphone target images for the iPad display, for example, and this suggestion would break those apps.

As a developer, I've been more and more often leaning towards using tools like paintCode or just writing code for custom widgets instead of trying to make the 4 different images for iphone/ipad/iphone@2x/ipad@2x. This is a win/win because it looks better (except at very low res) and keeps the size of the app down.

Having the app store serve different apps for different target devices opens a can of worms. For example, if you backed up on one device and restored on another, you could get the wrong one. I think Apple made the right choice in preferring to make sure your apps work everywhere rather than save storage at the cost of complexity. And if that means they're nudging the consumer to upgrade to the lastest and greatest, I can't blame them for going that route.