Maybe, people noticed that the primary subject might be more interesting if it wasn't exactly in the middle of the image.<<<
Comfort zones. Every culture has them.
Maybe over a period of time these suggestions, and others, acquired the status of laws to some people.<<<
Repeat something long enough and it's origins may be lost. The only things new it was said, is the history forgotten.
What is good art? Following the rules, or unbridled creativity? The Greeks were masters of framework and understanding. But, were they great artists or just artistic conformists?
My instructor back in the 70s gave a fellow student this advice once. Be careful, that composition doesn't work most of the time. Use your subject's components wisely and you can sometimes break the rules.
Take care, Gregory david Stempel FIREFRAMEi m a g i n g www.americanphotojournalist.com
