Charity doesn't evoke change. Research shows that for lasting change to take effect people have to be invested in their own transformation. So consistent charity or free services can actually harm service users, encouraging dependance and defeating the purpose of the help intended. As role models for their clients, social workers can't afford to set such poor examples.
Children who play sports learn to express their feelings of disappointment when the team does lose, a vital skill for developing resiliency. Sports give children the opportunity to learn to work together with others toward a common goal and a framework for developing the skills they will need later in life to achieve those goals.