Because he may be victim of a fraud? ie, the baby is someone elses? Because the actual biological father may want a role in his childs life? Because the state

Because he may be victim of a fraud? ie, the baby is someone elses? Because the actual biological father may want a role in his childs life? Because the state has a bit of interest in accuracy in its medical / birth certificate and other records? Because many births are to single mothers and the absent father may have certain financial and other responsibilities for the child?