Excessively trusting system, that was
I have fond memories of PRIMOS, as our school had a Prime 650 with a roomful of terminals back around 1980. The manuals were freely available on a rack in the terminal room. Perusing them, I discovered that what we now would call the root-level password was a) hard-coded and b) published in said manuals.
I understand that later versions of PRIMOS repaired those defects, but at the time, it was mind-blowing. Here's a roomful of kids, split between the I-gotta-get-through-this and I'm-in-a-candy-store crowds, and the keys to the safe were in full public view. "The honor system stretched beyond its limits", one of the pranksters called it.