People cannot allow killing someone because it goes against the fundamental principles of morality and ethics. Killing another person is considered morally wrong because it violates their right to life and infringes upon their autonomy. It also causes immense harm and suffering to the victim and their loved ones.
Society has established laws and regulations to protect individuals from harm and ensure their safety. These laws prohibit murder and impose severe penalties on those who commit such acts. The legal system aims to maintain order, justice, and the well-being of society as a whole.
Furthermore, the value of human life is deeply ingrained in most cultures and religions. Many ethical and philosophical frameworks emphasize the inherent worth and dignity of every individual, which includes the right to life. Taking someone's life is seen as a grave violation of this principle.
While it is true that humans have engaged in killing throughout history, it does not justify or validate the act. The progress of civilization and the development of moral values have led to the recognition that killing is not acceptable and should be prevented.
Overall, the prohibition of killing someone is essential for the preservation of human rights, the promotion of a just society, and the well-being of individuals and communities.