MonoTouch isn't really a cross platform toolkit. It is not providing a replacement API for Apple's APIs just allowing them to be called from C# and allowing you to use extra code you have in C# that Apple by definition doesn't have.

the Modern C# language provides many advantages over the Objective C used on the iPhone which does even have garbage collection.

If they intend to succeed in the Enterprise they should of encouraged MonoTouch not squashed it.