I buy it. Running forces you to, at a certain point, care about your physical, mental, and emotional well-being. I don't think that's necessarily going to happen at the 5k or 10k distance, but long distance running certainly can. If you are missing any one of those three categories, the run will not happen or will not go well. Nobody is forcing a person to run except for themselves, it's typically not a team activity, and distance training is largely a solitary activity. It forces you to be comfortable with yourself, or else how can you possibly expect to run 10, 12, 18 miles at a time?
Runners are a tribe, WanderingEng starts to touch on this. There's some friendly competition at the amateur level, but even just seeing another runner while I'm running is exciting. Yesterday, I ran 16 miles, and saw 8 different runners I personally know over the course of the run. It was amazing, and mentally it was amazing knowing "I can do this!". So, yeah, I buy this article.