I'm sure Microsoft has convinced themselves 1000 different ways that this makes great business.
However, the reality is that there will be no future for Windows Phone when the only brand it is associated with in phones is Microsoft. I consider whoever made this decision to be a total idiot. None of the reputation for quality of experience of Apple. None of the fight-the-power hipness of Android. None of the apps of either.
I consider it sad because I actually like Windows Phone a lot and own one. It's got noticably better performance and general quality of experience than Android, and was available at lower price point than Apple. The product was there, for once. Sad to see it fail for different reasons.