> Yes, it's great that you can write your own control flow constructs. So what? A sane language already includes those constructs, and they're known and understood by all users of the language without having to first read the documentation of some third-party lib (haha, just kidding, there is none – read the code, dummy!).

I do not believe that novel control statements are any different from novel functionality. A sane language already includes plenty of standard functions, but that doesn't relieve the need for more. New functions, like new control statements, may be poorly documented.

The fundamental power of computing is abstraction. Functions, macros and control structures are all different types of abstraction. The only way to build a successful, malleable large program is to abstract, and to avoid macros and new control structures is simply to require larger teams (because someone has to hand-write all the code which the computer could be writing for you) and more ad hoc approaches.