It need not hold back someone who wishes to harm others but secretly. Even open acts though not perceived to be so may be duplicitously harmful. A business person may be a mixture the unscrupuluous with other good and useful qualities. Ethical behaviour prescribes duties to everyone but the Golden rule may tend to favour the rich and powerful. This smacks of X-Files type science fiction and master race political rantings.
Moral beliefs change over time.
They differ between different countries and tribes, between different cultures in society or between social classes. We would abhor the practice of public executions as entertainment. There are different sets of moral beliefs held by gays about sex practices and religious devotees about abortion and the women's right to choice. Some would argue that it is a woman's right to choose. Others would argue that abortion involves taking a life.