Do you think school children should be restricted from participating in school activities if they have bad grades?

My daughter is a high school coach and keeps a close eye on players' grades. If they fail in class, they can't play. She does a lot of counseling to help them keep their grades up. She works with parents to help. Being on the team is an incentive to make good grades. She supports the policy of requiring passing grades in order to participate in extracurricular activities.