The rules of a sport often favor one body type over another. People with smaller limbs and bodies can change position more easily than larger people, so gynmasts and divers tend to be short. Basketball and volleyball favors height. Bicycle racing favors massive thigh muscles and a lack of weight elsewhere. American football favors massive linebacks and so on...
Most recreational sports can be enjoyed independent of body type. With dedication a six foot figure skater can be as good as most five foot skaters and a 5'6 basketball player can do very well in high school if he is very fast. But at some level of competition everyone is motivated and working hard and physical gifts as well as body type begin to become important. At the highest levels of sport it is often a gating factor - in the Olympics you need everything - plus some luck (like being in optimal shape on the right year, living in a country that has a slot and so on...)
NPR has an infographic on some olympic body types. It would be nice to see something like this for all sports. I've though about doing an average of a small number of bodies to produce silhouettes for each sport so comparisions can be made, but have never got around to it. It would be a good project for someone with access to a lot of body measurements of top athletes (not easy to come by).
What seems wrong is parents selecting sports for their kids at an early age based on their kid's genetics. (NY Times) - also another piece here. Few kids will ever ascend to the professional level and it is far better for them to find something they can enjoy. Sport should be motivation for a lifetime of physical activity rather than a complete focus. Most successful professional atheletes were active in many sports as a kid and had actual lives outside of sport. Cross training is probably a good and healthy thing in any case.