Apart from the fact that if people all behaved with a modicum of courtesy and mutual respect, this would be unnecessary, the manifesto seems perfectly reasonable to me - including about the small children, especially if the parents aren't snowflakes. We all know that children get tired and cranky and have lower coping skills and fewer articulation skills. Parents often disregard this in favor of what they want, to the detriment of all.
AB is doing what he can to mitigate the damage.
Moreover, he is using his words. He is telling you what he expects, and where the lines are.