I haven't read the article yet, but this is why being "content" never seems that descriptive to me. It doesn't describe the situation in which one finds themselves, it's a statement on their reaction. Some people always fight, some people throw a fit like a child, etc. Some people are content.
It's essential to find a source of contentedness in life, but it can be easily manipulated to become complacency. Are these kids content about being content?