Steinbeck definitely targeted people in positions of power who were corrupt and took advantage of people who were powerless. This is why he wanted to share the story of Kino and the pearl, to warn us about the greedy and the strong.
Steinbeck was clearly an advocate for the underdog. His portrayal of the doctor whose animal symbols are the hawk and the owl, represents also the greedy Europeans who came to the Americas to exploit the indigenous people.
Interestingly, Steinbeck had a friend who was a biologist, who traveled to the area in which the novella is set. Having traveled with this scientist, Steinbeck had the occasion to observe closely the native people who were pearl divers.
Steinbeck who was an author that was committed to social reform, and it is interesting that so many of his works of literature are aimed at pointing out the inequalities in society and the way that those that have wealth have a lot of it and use their position to exploit others. Kino and the treatment that he and his family receive when they find the pearl is a prime example.
Social reform refers to the idea of changing society so it is more responsive to the needs of the individual. In "The Pearl", Steinbeck points out the inequalities between the native Indian society represented by Kino and his village and the ancestors of the Spanish conquerors, represented by the doctor and the pearl buyers. Since the doctor refuses to treat Coyotito because he believes Kino has no money, he shows his prejudice towards Indian society. The pearl buyers try to cheat Kino out of the full price for the pearl. By pointing out the harsh treatment of Kino by both the doctor and the pearl buyers, his story becomes an argument of support for Kino and his people. As an writer, Steinbeck hoped that by telling this story, readers would be moved to help the Indians gain equality. Thus, he is advocating social reform.