I don't see your point, sarcasm or otherwise.
/sarcasm
To take your example to an extreme, is it unethical to trespass on someone's property? Is it unethical to look at someone's property from the street? Our concept of ownership would suggest that the former is unethical, the latter is not, but is that just because we have artificial ideas of ownership?
My ethical system includes IP ownership. I think it is unethical to use GPL code without releasing the source, for example.
James Madison, who wrote most of the Constitution, and Thomas Jefferson, who wrote most of the Declaration of Independence (and who were both later elected to the office of President), thought that IP had no basis in reality. http://classicliberal.tripod.com/madison/detached4.html and http://press-pubs.uchicago.edu/founders/documents/a1_8_8s12....
You have poorly defined what "ethical" means. So far the only clarification you have made is that legal and ethical are too different things. Some people disagree and define "ethical" as "law-abiding" which means that copyright infringement is unethical.
To be clear, I'm not saying you're wrong, I'm just saying that there is a degree of relativism to your statement. Just because you don't think that copyright infringement is unethical doesn't mean that people who do are wrong.
I'm not really a proponent of moral-relativism but ultimately I have to accepted that ethics are a human construct and as such disagreement will arise over its precise definition. For example, I think eating meat is unethical but most people don't. Does that make me wrong?
Not per se, but:
It's unethical to invade other people's privacy.
If you had a telescope with a special vision ray that could see behind walls, it would be unethical to use it to see inside people's homes and bedrooms.