Why did Okinawan people use karate?

Answer 1

They created it to help protect themselves from bandits and invading armies. There is debate as to whether the arts were developed by the rich, who had the time, or the peasants, who worked long hours. At one point, Japan had invaded and confiscated all weapons, so the Okinawans developed non-weapon fighting techniques.

Answer 2

They used it to protect themselves against bandits. The use of weapons was forbidden by the rulers, so the natives developed unarmed methods of protecting themselves.