They are not trying to cause someone to stumble. Some feel badly about themselves because they lack the formal education that others have. They feel dumb or inferior. David was a shepherd as was Amos. Abraham Lincoln spent less than one year in the classroom, but he was recognized as a brilliant leader.
Children often suffer low self esteem because of the way their parents live and conduct themselves.
Perhaps they have a parent on drugs, in prison, one who drinks, goes out partying dresses immodestly or because they come from a broken home. One of the most recognized reasons for low self esteem today is physical and emotional abuse. A parent or spouse may physically beat and scare a person so as to make them feel worthless. We must also learn to forgive ourselves if we have repented and God has forgiven us. Self esteem, like happiness, usually eludes the person who seeks it directly.