You aren't missing anything. It's a good point. We're beginning with what is central in C and then moving outward. C, as designed by Ritchie, and for the first

You aren't missing anything. It's a good point. We're beginning with what is central in C and then moving outward. C, as designed by Ritchie, and for the first 40 years of its existence had no official support for multithreading, so this can hardly be called central. If we add support for multithreading it'll be after finishing with C89 and C99.