Reverence demands that holy things receive special treatment and handling. Although approved by the Church, receiving the Eucharist in the hand is not special behavior. It is familiar behavior. People feed themselves daily. There is nothing special or mysterious about handling a piece of food and putting it in the mouth to eat.
Touching food makes people familiar with what they are about to eat.
Should there be a question about a certain food, handling it is one means to decrease the mystery. Familiarity, unfortunately, spawns complacency. Complacency becomes manifest through irreverence. Consider the irreverent behavior of many Catholic school-aged children in church, children who, for the most part, were never encouraged to receive Communion on the tongue, and who were never taught reverence. A degree of mystery and reverence used to be inculcated in children in the days when the priest was the only one allowed to touch this Holy Food .