Microsoft/Nokia sold tens of millions of Lumia 520 devices.
I doubt developers care what region their customers are in. A customer is a customer. Unless you can charge customers who have more expensive/faster devices more than customers who have lower end devices, I don't see the difference from a developer's perspective.
The main advantage that Windows has over Android is that Windows apps primarily use native code, whereas a significant chunk of Android code runs Java, thus, is more bloated. On low end hardware Windows just runs better.