atexit() example. exit (1) in main, but $?=0

This atexit function just look like another way to obfuscate programs.
Example:

[rtg@rtgCent cpp_exa]$ cat atex.c
#include <stdio.h>
#include <stdlib.h>

void mine(void)
{
printf("mine!\n");
exit(0);
}

void yours(void)
{
printf("yours!\n");
exit(1);
}

int main(int argc,char **argv )
{
 atexit(mine);
 atexit(yours);
 printf("exiting...\n");
 exit(1);
}
[rtg@rtgCent cpp_exa]$ gcc atex.c 
[rtg@rtgCent cpp_exa]$ ./a.out 
exiting...
yours!
mine!
[rtg@rtgCent cpp_exa]$ echo $?
0