I was curious seeing this thread, and I just looked and don't get it either. AFAICT the CP/M references could have been entirely omitted and nothing in the narrative about TMP and TEMP would change.
Except that DOS was made to have its first programs ported from CP/M, so it’s relevant to explain that there were no environment variables to inherit from CP/M and no developer habits or program standards to inherit from CP/M programs.
Except that DOS was made to have its first programs ported from CP/M, so it’s relevant to explain that there were no environment variables to inherit from CP/M and no developer habits or program standards to inherit from CP/M programs.