For the customer though the difference was not that dramatic. My wife had a WP7 device and I liked it enough that I replaced my android phone with a WP8, and wh

For the customer though the difference was not that dramatic. My wife had a WP7 device and I liked it enough that I replaced my android phone with a WP8, and while it was clearly better than 7, it was not dramatically better. At the time the lack of backwards compatibility was baffling for the WP7 buyers I knew, and all of them switched to iphone or android after that because of being burned by that transition. I had a similar experience when they went to WP10. While WP8 was a fast, stable and highly usable OS, WP10 was a dumpster fire (for me as a user, cannot talk about underpinnings). Constant crashes, slow, terrible battery life. This was a widely shared experience among WP10 users as far as I know. And on top of that there was another software transition that all but guaranteed no apps properly jumped to the new platform. Looking back on it I think jumping to WP10 instead of carefully incrementing WP8 was the big mistake, and rolling out WP8 without a way to make the transition easier on existing WP7 buyers was the lesser one. I don’t think a perfect execution would have saved microsoft though: they would have always been third and it is pretty clear developers cannot support more than two mobile platforms properly. The app situation would have always been bad, and without all of the popular apps a smartphone is dead in the water.