Like anything else, I think every opportunity (whether sports, academics, career, family, etc.) is best pursued in balance with everything else. Though I am built (and genetically predispositioned) to be very athletic, I have to admit that growing up, I was not particularly interested in sports. I participated because my parents encouraged me to, or because my friends did it, and I usually had fun, but playing sports has never been on my top ten list of favorite activities. I still feel the same way today. I don't even really like watching sports.
That said, I do think sports provide the opportunity for learning many life lessons in one of, if not THE healthiest way possible. Team sports teach leadership, dedication, teamwork, responsibility, trust, communication... the list is almost endless. Even individual sports, such as golf, teach lessons like perseverence, dedication, how to learn from mistakes, etc.
Like anything else, it can be dangerous when sports are made to be the most important thing in a person's life. However, I do believe that they are inherently positive, healthy, and important when included in a life that is balanced.