As a volunteer coach to youth team sports, I have seen many young kids come through the sports programs. Some kids are athletic and love sports. Others are the "non-sporty" kids. Here is my point of view as a youth coach regarding kids quitting.
1. If the child is miserable, let them quit. It’s important for a child to try a sport, but if they don't like it, they don't like it. In most cases, it's the parent who signs their child up either because the parent was once "a great athlete" or they want their child "to be active." "Non-sporty" kids usually don't want to play sports.
Youth Team Sports Are Not Daycare