Certain cultures punish dreamers for wrongs done in dreams because of the belief that if the dreamer has seen that act, therefore they are capable of committing it and should be punished. This attitude dictates that the dreamer’s moral character, or immoral character, persists in dreams.
Why do people dream of doing actions they normally would not do in waking life? This could support the hypothesis that the dreamer is indifferent to morality. they dream of doing things that they normally would not do when awake. A naughty man remains bad in dreams, while a good man remains virtuous in dreams. This is why we should listen to people when they talk about their dreams. We can learn about their nature, except when people lie and invent dreams.
There was a Roman Emperor who punished a man with death, after hearing that this man had dreamed of killing the Emperor. At that era, the Romans believed that if a person dreamed it, they had thought about it during the day’s waking reality. This argument follows the hypothesis that dreams continue waking life and the cycle continues with waking life being guided by dreams. Have you experienced dreams that continued your waking life? Have you seen waking life that was a continuation of dreams?
Some tribes in Native American Indians also believe that the dreamer is responsible for having dreamed wrongful acts and should be punished. You can read more in this post called Guide to Dream Interpretation for Native American Indians.