Why do you think human beings have so many different conceptions of what is moral?

Anonymous
The list of different moral opinions that have humans have is almost infinite. For example, the Aztecs believed human sacrifice was moral. We think that is crazy. Some people believe abortion is moral. Others don't. Some Catholics believe birth control is immoral. Some people believe socialism is moral. Others disagree. Some people believe homosexuality is immoral. Others disagree. And I mean in non-Western countries like Africa and India too. For example, in India killing a cow is immoral. For some Muslims, consuming alcohol is immoral. Why can't we agree on what is moral and immoral?
Why do you think human beings have so many different conceptions of what is moral?
2 Opinion