Why are the children of slave women enslaved in Islam, especially since the newborn is not to blame for his mother being a slave?

The child of a slave woman is free if he is born of her master, or from intercourse under a misconception with a free man, or if his freedom was stipulated. He is a slave to his mother's master if the slave woman marries a free man or a slave, because the child follows his mother in status, whether free or enslaved.