Why is D unpopular?

[Walter Bright]

I spoke with Atila a year ago on his excellent dpp. He handles the 
metaprogramming macros with a handbuilt translation of them. This works, but has 
to be constantly tuned. The lack of a general solution was what I was referring to.

I said I wanted to incorporate his work on this into ImportC's handling of the 
preprocessor macros.

With this:

   https://github.com/dlang/dmd/pull/14121

the following ImportC program compiles and runs:

   #include <stdio.h>
   void main() {
     printf("hello world\n");
   }