I think it comes down to that photography has no definitive right answer.
Some people can create grainy, overexposed, super-high contrast photos, while others like to emulate Ansel Adems from their shoes to their paper.
Thing is, people in the past, often used dumb, "throw-away" p&s cameras which probably had one or two modes of exposures, regarding taking the photo -and people managed to get photos back then.
Many people operate similar, letting the camera meter away, others are very strict, others again. rely on long experience and others again don't even use a meter.
Some give advice, based on the theory of Adams, with references, others give advice on what seems to work pretty well and consistently, but it an easier approach which in the end gives a different explanation to how things work.
I see people share their various methods and experience in that thread and it is interesting to see the variety. The internal battles are easy enough to skim trough, I saw one thread on here, which begun by criticizing Hasselblad's and the way they are constructed, that discussion went from sour to a joy-fest on how some particular brand of ham-radio worked