Have you ever seen submissions to IOCCC or Underhanded C Code Contest? That is what too much syntactic flexibility looks like (if taken to the extreme).
If you want your code to be secure, you need it to be correct. And in order for it to be correct, it needs to be comprehensible first. And that requires syntax and semantics devoid of weird surprises.
If you want your code to be secure, you need it to be correct. And in order for it to be correct, it needs to be comprehensible first. And that requires syntax and semantics devoid of weird surprises.