Blaming OS is pointless, as (I assume) none of us have any insight of the actual intentions with their APIs. If they want to change how some methods act, it's completely up to them, and those changes might be even fully justified - e.g. they add a required parameter to a method or a class constructor to boost security.

Saying they should add a workaround for older application is often a matter of philosophy, not of a simple bugfixing (not that bugfixing would be simple in the first place). Yes, they can do it, and end up like Windows - having to support APIs from 15 years back in their latest system to avoid annoying users. The cost? Complexity and size of the software. Backward compatibility incurs additional costs on testing, documentation and support. Wanting to target multiple devices with 5.0, they also need to keep size and performance in mind. Etc.