The LCD argument is false here, there is nothing that can be done in Objective C through public APIs I cannot do with C#/Xamarin. The day after iOS 6 was released, Xamarin had an update to Monotouch. The betas were available before that as well.

I think for me, having a decade plus of C# experience this was a no-brainer. Moving from building web apps to mobile on a new platform was a big shift and removing the confusion of a new language helped smooth the transition.