It's verbal abuse. There is never, EVER, any valid reason for a father or a mother to be unkind to their children. Oh, to be sure, they have to punish and correct their children, and such measures are harsh in their very nature. But, like the way of God, punishment is to be delivered with kindness. Unkind words, words that demean, that humiliate, that cause their children to suffer severe damage to their own sense of being a human being and a child of God are words that are always out of place, always reprehensible.
Anger is sometimes necessary, humiliating another, even a child, is never appropriate.
The reverse is just as powerfully and just as truthfully so. Perhaps that is why our Holy Mother Church places this feast of the Holy Family before our eyes each year at this time. Jesus was the product of a family in which God's gracious goodness was powerfully present. Jesus grew in wisdom, grace and favor before God and men, Scripture tells us. With a mother and a father who lived in deep and steadfast commitment to God, to each other, and to Him, and who lived every moment of their lives in the gracious kindness of God.