He became a hero among the commoners because he was a thief who targeted only the powerful people, and also because of political pressure under Hideyoshi TOYOTOMI who was very unpopular due to his failure in trying to invade Korea.
相手は権力者のみの義賊だったため、当時は豊臣政権が圧政や朝鮮出兵の失敗で嫌われていた事もあり、庶民のヒーロー的存在になっていた。