It's not just that humiliating people, of any age, is a nasty and disrespectful way of treating them. It's that humiliation, like other forms of punishment, is counterproducti ve. 'Doing to' strategies -- as opposed to those that might be described as 'working with' -- can never achieve any result beyond temporary compliance, and it does so at a disturbing cost.
Trying to motivate yourself with fear is like screaming at a child, “Do something, dammit!” You’ll either freeze up or act in counterproducti ve ways. Fear widens the knowing-doing gap. Don’t use it.