You appear to have reduced "sports" to "American football". There are a lot of sports out there. Most of them do not come with risks of debilitating head injuries. Participating in sports is a great way for people to stay healthy, build confidence, be part of a team, etc. By and large they are a great thing for kids. I can't imagine how one would find data for this, but I imagine that the percentage of sports-loving parents who push their kids to be pro athletes is about zero.