dash as switches were always explained to me as from Multics. Having used DEC systems, Univax and IBM systems originally with cards and ASR33s, I was not yet stubborn enough to see value one way or the other (the links in ROMs in my fingers were not yet programmed). By the time I left CMU and the glass tty was all I was willing to use. I had become a UNIX/C person more than anything else, so slashes as switches (and upper case and case folding) had become annoying and just seemed wrong.