Children are not expected to be in full control of their emotions. Children are not expected to be experts in any field. Children are not expect to create laws for the country. By comparing them to children, we are saying they do not have the mental maturity to handle their respective duties. Which is a perfectly reasonable way of putting it. Children should never be in charge of anything important. They should be figuring life and themselves out before their soul gets caught in the gears of capitalism and is crushed for its value.