Most people understand that Windows is used by a variety of people who have a variety of needs, ranging from corporate server to workstation to POS terminals to home PC and beyond. Most people accept that whenever Microsoft updates Windows, it has to balance the competing requirements to find some kind of workable compromise. There is however another set of competing requirements that many do not really register, even those that call themselves power users or are IT admins. It is a conflict between developers/programmers and Microsoft itself.
Developers are ultimately the ones who write applications used by users whereas Microsoft develops the OS these applications run on. A common shared goal between the two is the desire that applications previously written continue to work. Users use Windows not to use Windows, but the applications that they need after all. Developers on the other hand have finite resources and time and the need to constantly tweak an existing program because of an unstable ABI/API is often an unwelcome distraction. Even worse for developers is when support for an API is eliminated outright, which would require a complete rewrite. Loss of a platform happens much less in the Windows world than in the open source world, and even there it is a rare event because of how pissed off the developers who make up that sphere would get. Developers also often want the platform that they are using to be continually updated either with bug fixes or new features to make certain tasks easier. Contrary to what many users might think, we generally want to be able to keep supporting our customers/users and want to add new features while keeping existing ones working. This task becomes very difficult however once a framework/platform is deprecated as certain things may simply not be possible without underlying upgrades.