[wnissen]

Yes, this is what's being left out. The standards are not designed for someone who is capable about writing an essay discussing the tradeoffs and and evidence for various standards. The standards are designed for someone who is not capable of writing, period. Not that people working in commercial kitchens are unintelligent or untrained, but some are, at least in the language in which they're working. "Only use stuff that says NSF, keep cold under 40, hot over 140." That can be conveyed in a few seconds, to almost anyone.

Furthermore, it provides you a margin of safety. 165 for chicken is going to be pretty dry for white meat, but I'd choose that over medium rare!

If the guidelines occupied a poster-size tree it would be much more difficult to follow them and the consequences would be much more severe.

I also make it a point never to take food safety advice from anyone who doesn't know the difference between "sanitized" and "sterilized".