The presence of a HOA in a neighborhood keeps the neighborhood operating smoothly after the developer leaves. The Homeowners form a Board of Directors and many groups branch off from
the Board. There can be an Architectural Review Group that oversees the covenants and architectural guidelines. This helps keep neighborhood values up. There are social groups, book clubs, neighborhood
beautification and clean up days, BBQ's, Christmas Decoratations, Neighborhood Watch Patrols etc..
Simply put, homeowners who are active and involved in a subdivision protect property values and add to the desirability of the neighborhood.