What is a VM but an intermediate portability layer? That's what VMs are made for, to be able to run the same VM code on different machines or different OSs with

What is a VM but an intermediate portability layer? That's what VMs are made for, to be able to run the same VM code on different machines or different OSs without having to recompile. You don't use the OS's APIs directly from Java or NET, that's the whole point of the exercise. And if you find a way to do it anyway, you have defeated the purpose of the VM and could as well have compiled to native code.