I think for some families and communities there is a huge amount of pressure to play sports, especially baseball, football and basketball for boys. This is partly because there a huge popularity boost for successful athletes in our communities especially at the high school level in suburban and rural areas. Others have a "family heritage" to uphold. Finally, in many impoverished communities, being a professional athlete is seen as their ticket out of the ghetto - and sometimes seems like the only viable option.
In the Dominican Republic there are baseball "farms", training camps for children as young as 8 that are sponsored by professional baseball. These camps do a lot of good work educating kids as well as teaching them about baseball but because they're so competitive to get into, outside of the schools bad things happen to slant kids' odds of getting in.