Ethics are rather personal, at some level. While one might argue murder is flat wrong, other questions of ethics become more touchy and personal.

No, I don't think ethics should be taught in a hunter safety course. At the same time, the instructor can make the point that all hunters represent other hunters when they are afield and in the public. If we do things which are strictly legal but which cast our sport in a negative light -- like shooting animals in a high fence environment where the element of "fair chase" is pretty skimpy -- we are liable to have our sport denigrated by the anti-hunters and ordinary non-hunters, and our sport outlawed. When you drive to field with a license plate reading "if it flies it dies" or "if it's brown it's down," this is going to leave a bad taste in the mouths of some people and reflect poorly on hunters.