Sounds like the short answer is "because there was no standard for the variable set by MS-DOS from the get go".
replyThe background is that the issue hadn't existed in CP/M because there hadn't been environment variables. Perhaps if the issue had already been seen in CP/M, the developers of MS-DOS might have defined a standard variable to avoid it. Maybe. Other than that it doesn't seem to have much to do with CP/M specifically.
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.
replyExcept 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.
replyWhich is irrelevant to TMP or TEMP.
replyIt could simply be: When envars were added to MSDOS…
Multics had envars in the 1960s and Unix in the 1970s, why were they ‘added’ to DOS when it was so close to an older OS, why didn’t it inherit them from CP/M? Did it get TMP from CP/M and introduce TEMP because computers were bigger but then?
replyDid Multics actually have something really similar to the much later envars introduced in Unix?
replyThose questions appear awfully overfit to the current blog post.
replyThat comment feels awfully cherry-picked to the perfect untestable rebuttal based on what you want to be true.
replyHow did you measure the fitness and decide it was 'over'?