Again, this conversation is about Xamarin the mobile app studio. There is zero ambiguity in this, so it is perplexing that you keep bringing this up.
The context is the cross-platform app creation toolset. It generates extremely poor quality code, usually at a significantly increased development time (quite contrary to the promise). This is the case found by almost everyone who uses it, which is exactly why most teams have an Android project, fully using the tools of the platform, and an iOS project, fully using the tools of the platform. If Xamarin were heavily used, Windows Phone wouldn't be so generally unsupported.