In ancient times there was no lab to see what's inside the body and what kind of factors tend to interfere with health. Having a blood with an acid pH looks like an easier path to critical problems according to several studies, and the charts clearly show what kind of nutrients are acid.
Meat, fish are two important acidifier mentions because even today, where it's possible in multiple locations to completely avoid taking resources from living and autonomous animals, the demand is habitual. The reality says that in multiple locations there's no true necessity and of course with another social organization it could be completely possible to avoid losses of this transcendence providing alternatives to the entire population.
Perhaps the pH scale it's the secret that differentiates who has a good nutrition and the people that always go to the coffee, sugar, soft or energy drinks, meat, fish, chocolate, alcohol and alike. As any aspect are statistics, this should increase the risk in some points.
To print a chart and fix it to the fridge seems an interesting practice. The body experiences and provides what takes.