It's more than just a sport. It's more than just a martial art. It's a science of life.
More than kumite (sparring) or kata (form), it develops the mind and character for navigating real life in all its glory and even (or more importantly) its frustrating aspects. A positive self image, respect, and leadership qualities that enable a person to put things in perspective and act in a way that is appropriate for the moment in the spirit of promoting what is good.
That's why it is a good place for children to be in. As a child goes through the classes, parents slowly grow in excitement as they see how a child develops as a karateka and develop character in the process.