From reading the article, my understanding is that the almost two year old child was screaming on and on, annoying the staff and other guests. After attempts were made by the staff to ask the family to keep the child quiet or leave, the parents did nothing, so the frustrated owner yelled at the kid.
If that sequence is correct, I am 100% on the owner's side. I have kids that often had trouble being quiet in public, but they received appropriate discipline until they learned how to behave. By not stopping the child's outbursts, the parents here were complicit in ruining the meals of other guests. I view it in the same way as if the mother herself was screaming because parents are responsible for their childrens' behavior.
Those parents probably let the child do that at home too. More and more, children are not being told how to act in public. Heaven help society.