I am wondering how many commentators in this thread have actually read the linked articles.
As I understand it, the parents were put in jump seats and the 10 year child in the only remaining regular seat, i.e. next to complete strangers. In flight, the parents blocked the galley and therefore moved (or were moved) to empty floorspace in the back of the cabin. They were joined there by their 10 year old who apparently got bored / frightened / whatever sitting alone in her seat. I don't see how anyone can reasonably put any blame on the passengers.
Now, what I find really interesting is that in these days or sardine-style air travel with seats crammed into every corner of an airplane with as little seat pitch as possible, why would an aircraft have sufficient floorspace that a family of three can have a relaxed sit-in as per the pictures? It has been suggested that a row of three seats was taken out. Is it a common occurence that seats taken out are not replaced at the same time? Why wouldn't you simply leave the seats where they are and make them inop until they can be replaced in one go?