> "What if you cast a string pointer to a function and called it! Huh?" and I explain that is perfectly legal C

I would argue that it's less than "perfectly" legal: The C standard lists it as a "common extension":

  J.5.7 Function pointer casts 
  A pointer to an object or to void may be cast to a pointer to 
  a function, allowing data to be invoked as a function

And on a practical level, it seems to me that the increasing proliferation of NX enforcement is cramping the acceptance of this extension.