Maslow's Hierarchy of Needs states that humans have the following five needs in this order: Physiological, Safety, Belonging, Esteem and finally Self-Actualization. Physiological needs include water, food, sleep, shelter and clothing. Safety needs include security, stability, dependency and order. Belonging needs include social relationships with other humans. Esteem needs include self-respect, achievement, adequacy, mastery and competency. Self-Actualization needs include utilizing abilities and talents to the fullest extent.
The point I would like to make is that Esteem comes AFTER Belonging. It is such a common notion that is expressed often condescendingly that one's self-esteem must come first, before wanting to belong.
"Glasser indicates that a useful perspective for viewing identity is in terms of a success-versus-failure orientation. Those who develop a success identity view themselves as being generally successful; people who develop a success identity do so through the pathways of love and worth. People who view themselves as a success must feel at least one other person loves them and also that they love at least on other person. They must feel that at least one other person believes they are worthwhile, and they must feel they (themselves) are worthwhile. To develop a success identity, a person must experience both love and worth, particularly during childhood. A person can feel loved but not feel worthwhile. Worth comes through accomplishing tasks and achieving success in the accomplishment of those tasks. A person can feel worthwhile through accomplishing tasks (for example, a successful business person) but believe she is unloved because she cannot name someone she loves and who loves her. Experiencing only one of these elements (worth or love) without the other can lead to a failure identity." - Charles Zastrow, "Introduction to Social Work and Social Welfare: Empowering People Ninth Edition"
So many people have low self-esteem because they have yet to have their need for Belonging fulfilled due to a lack of a healthy intimate relationship with a parent(s). Therefore, it is not the person's fault as is so commonly eluded by ignorant people.