It's hacking, sure. Just like using a hex editor to enter machine code directly. It's not C code, though, despite what the author claims, and it's not showing some clever way to hack C code that makes the author look Klever. SO go ahead an be impressed some something that isn't what it claims to be and doesn't do what it claims to do.
Of course it's C code. It parses, and compiles, giving undefined behavior.
If C wanted to insist that main is a function, it could. That could be in the standard, and then these clever hacks wouldn't compile.
So no, you're dead wrong about that claim. So I'll go ahead and not be impressed with your commentary.
Of course a standards compliant C compiler could give you nasal demons, or delete your root directory, so it's not the sort of thing one should push to prod on a Friday.
