The moral values in the story are best seen in the townspeople's reactions to something so unique, different, exotic, and strange as this man washing up ashore, dead, and who looked so strikingly.
In a morally-corrupted society, a finding of this kind would have provoked chaos, and people would have cathartically expressed their own fears and horrors of life through this man's death.
However, the village to which Esteban washed ashore was so distant from society, that not even boats stop in their shores. Hence, Garcia Marquez is giving us an allegory of innocence: Something that keeps itself guarded from the intrusions of malice and the mundane.
The moral value is then, that in a place where innocence is king, the chances for finding kindness, honesty, and love are equally possible. The townspeople valued the person of Esteban in death as if he were alive; they took moral and physical responsibility for his well-being, they gave him dignity, and they created a personality for him.
They gave him a form of existence even after death, and he, in turn, gave them pride, self-sufficiency, motivation, unity, and collective love. The synergism between the dead and the alive, the known, and the unknown, and the common with the strange all are bound together through love, and the love Marques presents here is only possibly achieved through the agency of innocence.