If a Child begins playing a sport at a competitive level to early, it might easily occupy a large part of their childhood, which a person only gets to live through once. For example, say a child begins homeschool at age 11 to attend a daily soccer academy and to travel for tournaments. While the child's daily focus is placed upon headers, passing, and dribbling, the child will miss out on the typical child events such as school, movies with friends, and other things a typical child does. This lack of a normal childhood could greatly affect how these kids will turn out as adults.
If a child excels in a certain area, it certainly benefits them to pursue it. However, to over pursue it hurts the child. Parents who try to live vicariously through their young stars are another big issue. When a parent pushes a child too strongly to do something the child does not want to do, all so that the parents can boast about their kids, the child is more likely to be unhappy and later on to have anger or stress issues later on in life.
Kids who only play sports all day, every day may one day go on to make millions professionally, but may never again truly fit in to everyday society. When a child's schooling on social skills is replaced by one on proper volley technique, how many true friends will that child have when they grow up?
While it is nice to see young athletes who excel at their sport do well at higher levels, it is even better to see them do well on the field AND in their daily lives. Sadly though, in sports today, fans and coaches care more about the players' performances during the game and less about the parts of young lives that were been sacrificed on the way to the top.