- High adoption rate of iOS6
- Cool iOS6 APIs (Autolayout, UIKit attributed text, indexed subscripting, etc)
and they decide to write for iOS6 only. They could support iOS 5, but the work is not worth the reward with the adoption rate of iOS6 being as high as it is.
For developers with existing customers, it is a different story.
Subscripting requires runtime support in the form of `-[NSDictionary objectForKeyedSubscript:]` and pals , available only in iOS6 and above:
http://developer.apple.com/library/ios/documentation/cocoa/r...:
https://developer.apple.com/library/ios/#releasenotes/Object...
I've spent many hours on other applications, mostly Mac, where the time spent making something backwards compatible was never really worth it. Example: I worked on getting fancy animations in an app that had to support Panther, which didn't even have NSAnimation support. However at this time Leopard had just came out and had all the new Core Animation hotness. Needless to say I would have saved countless hours if I didn't try back porting new features to older OSes no longer supported by Apple.
I guess this is just what we get when we buy Apple products. They are damn good at making last year's awesome product look obsolete the next year.