Centenarian interviews and general interest articles are a firm favorite in the mainstream media - largely, I suspect, because they require little work on the part of the journalist and are almost always well received by the audience. An unconscious assumption is at work in the reader; that a centenarian has something constructive and helpful to share about how they achieved such longevity ... but this is certainly not the case in reality. If pressed, could you provide a rationale for some random facet of your health history? Of course you could, but how likely are you to be right?
You can't do anything with a sample of one, and it's very hard to pin down even the obvious whys and wherefores of your own health, never mind relative progress or decline over decades. Think about the time taken to understand how specific foods alter your moods, for example - and that's an easy task in comparison to most. It has taken years armed with modern biotechnology to even scratch the surface of human longevity, and this working from huge groups of the old and healthy.
The timeless, easy popularity of centenarian articles illustrates something fundamental, I think - that most people really are interested in living much longer, healthier lives. It's just a question of how you present the options.