I think that captures the why. Perhaps with a hope that a single UI between the two devices might be cheaper...
Windows 8 was a culture shock, but at least was clear in what it wanted to be. Personally I found it (and to a lesser extent the "mostly like a phone" UI of Win 10 and current MacOS) to be a mistake - I want a distinct and appropriate metaphor for a desktop rather than using it like a 27" tablet. People have dozens of apps and windows open, not one or two at a time.
Win 10, for me, is a mess. The whole flat thing went much, much too far, there's dozens of remnants of the Win 7 way of doing it in dialogues, settings, workflow etc. Win 7 is probably the nicest, and most coherent look Windows managed, but for workflow Win 2000 often had the edge! e.g. every version of Windows since 2000 has reduced the power of search, but made it increasingly obvious that it's there.
Windows 8 was a culture shock, but at least was clear in what it wanted to be. Personally I found it (and to a lesser extent the "mostly like a phone" UI of Win 10 and current MacOS) to be a mistake - I want a distinct and appropriate metaphor for a desktop rather than using it like a 27" tablet. People have dozens of apps and windows open, not one or two at a time.
Win 10, for me, is a mess. The whole flat thing went much, much too far, there's dozens of remnants of the Win 7 way of doing it in dialogues, settings, workflow etc. Win 7 is probably the nicest, and most coherent look Windows managed, but for workflow Win 2000 often had the edge! e.g. every version of Windows since 2000 has reduced the power of search, but made it increasingly obvious that it's there.