What is the purpose of "non-profits"?

From Managing the Nonprofit Organization, Principles and Practices by Peter F. Drucker,

A business has discharged its functions when the customer buys the product, pays for it, and is satisfied with it. Government has discharged its function when its policies are effective. The "non-profit" institution neither supplies goods or services nor controls. Its "product" is neither a pair of shoes, nor an effective regulation. Its product is a changed human being. The non-profit institutions are human-change agents. Their "product" is a cured patient, a child that learns, a young man or woman grown into a self-respecting adult; a changed human life altogether.