Dear OP: why do you think the Win32 C APIs still exist? Microsoft have offered .NET for Windows since 2001. It does everything you're requesting but it hasn't replaced the completely hideous Win32 C APIs.

Bluntly: there is a class of programmers and programs that cannot be written without:

* C linkage

* Calling of and calling from C

And a further class of programs where:

* Garbage collection

* Significant runtime

* Safe code

Make acceptable performance impossible. This class of programs includes .NET itself which is entirely written on top of the Win32 C APIs.

If you want a runtime on top of Objective-C, you're welcome to write one yourself. It could offer everything you're requesting without needing to change anything about Objective-C.

Oh wait, there are literally dozens of runtimes on top of Objective-C. Not to mention official bindings to Python and other languages. Sure, none of them are very popular but if you want to write in something else: go ahead.