I don't think MS has to pushing anything. Nobody likes W8.1 and W7 will become Vista sooner rather than later and eventually everyone will use W10.
I know virtually nothing about MacOS, but if it works similar to Android (regarding updates and hardware compatibility), then that doesn't apply to Windows.
When I say similar to Android, I mean this: I've heard of Samsung patching older Android versions with modifications that would slow down the phone and reduce battery life, but that's only becuase it's mandatory to buy newer hardware to get newer software in the Android world. That doesn't happen with Windows. If anything, it's the opposite. I've found W10 performing equally or better in older hardware. So unless MS is genuinely concerned with user experience (sounds harder to believe thaym all the conspiracy theories put together), then I don't see why MS would do this.