Earlier quoted context omitted.
This is based upon attempting to use the products to build some solutions. The Xamarin advantage is in the cross-platform tooling (if I'm making separate code for each, why would I bother with a layer of abstraction?), but when used it generates a compromised result. It is perfectly fine for some relatively simple things. Basic information apps, etc. But it isn't long in complex apps before the abstraction is leaking…
"Compromised" how? "Leaky abstraction"? What is the abstraction and can you please provide specific examples of the leak? It worked between Mac and Windows on very complicated apps. It bridged Linux and Windows for tweaky MVC stacks a decade ago (then they wisely sharpened their focus.) It got the job done pumping data through hardcore game engines. The network stack is proven robust. You're talking about it like it'…
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.