Why do ethics create conflict?

Answer 1

Just like any other concept everyone has their own and believe that everyone else should follow it. Or people who are set in one ethic are surprised and dismayed at another groups apparent lack of the right ethic or acting in a way that seems unethical.

Answer 2

Because ethics is based on moral values. Moral values are interpreted in many different ways. Some of the ways are religious, non-religious, and cultural based ideas -- all which tend to clash at times.