One of the main issues in talking about ethics is that people are referring to different aspects. Ethics can be talked about in a number of ways.
Some people separate ethics into:
Meta: what it means when people talk about right and wrong
Normative: what is actually right and wrong, or how should we decide
Descriptive: what do people think is right and wrong
Applied: what actions should we take to do what is right
These are all very interesting but different concepts. One person may be talking about normative and someone else may be talking about descriptive. This can cause a lot of disagreement and confusion. (this problem also happens in a lot of other areas of disagreement between people)
This is not to say people do not have real disagreements on the topic. It is just that many of the disagreements have to do with what aspects of ethics people are referring to.