The VM is irrelevant, C compilers can call each others code, why can't code from one C++ compiler call code from another? It has nothing to do with the VM and

The VM is irrelevant, C compilers can call each others code, why can't code from one C++ compiler call code from another? It has nothing to do with the VM and everything to do with the implementation of namespaces/calling conventions being 'undefined' It's insane.