CONTEMPLATING METHOD. At Blogs for Industry, a useful clinic on the use and abuse of "moral relativism" as a category.

The truth or falsity of moral judgments, or their justification, is not absolute or universal, but is relative to the traditions, convictions, or practices of a group of persons.

That stance is useful for the observer who wishes to understand why people do the things they do: note that it does not validate, let alone excuse, those practices.