100% true. I'm going to piss many off by this statement I'm sure... but if you are a web developer Xamarin offers no advantages against PhoneGap/Cordova I don't know anyone that is "just a C# developer" and hasn't done any web development, maybe Xamarin makes sense for those.

Take a look at Ionic Framework if you think PhoneGap/Cordova can't provide a native look and feel.