I remember a popular panel speaker saying that "Children should be seen and not heard ... and preferably not seen either" A bit extreme the punch line but I think the first is a valid attitude.
These days, and for several generations, it has been 'normal' to tend to ignore people other than oneself and if ours disturb others the concept it that it is 'the others' problem. Consideration for others seems to have gone out the door and we have children flying in planes making a racket and somebody who makes a comment about them to a freind, but is overheard ... shades of stage whispers perhaps ... is crucified as being un reasonable.
Then it turns out that the husband/ father was sitting beside the commentor and apparently doing nothing to keep the children happy and quiet ... that's womens' business anyway.
Side issues like one part is Labour and the other ACT add nuencess to story.
But it all boils down to bad parenting and unbringing of children rampant these days when corporal punishment is an offence and children are simply permitted to run wild and un controlled and thereby not taught to have consideration for others when out of the home environment.