Long story short, iPhone is a great platform for apps, as we all know. But it’s also a great platform for Microsoft apps—it’s arguably the best mobile platform for Microsoft apps—as well. And that makes it a lot more interesting. And a lot more useful.
It is surprising that you get a better experience of Microsoft’s own apps on iOS but that could lend the possibility to not just the popularity, but the ease of development due to software constraints and fragmentation on other developing platforms. With Google not exactly supporting Windows Phone anymore, it would appear Microsoft supporting Android is due to necessity. Even with Microsoft being the 3rd in the top players, they still maintain their class of putting users first – would Google do the same in their position? I doubt it.