Principles are, at least to some extent, inherently aspirational.
You put them in your founding documents and spread them in your rhetoric because you believe that, even if people are not following them now, it is important to make sure the people in the future know "This was our goal. This is what we think is a good ideal to shoot for." That way, they can see it, compare it to the practice, and say, "Y'know, maybe we should do better."
Here we are in the future, and it's not right. We can see the principle, and compare it to the practice. Will we shrug, and say, "Eh, everyone knows that sort of thing is just blue-sky idealist thinking. No one really thinks it can work in the real world."?
Or will we say, "Y'know, maybe we should do better."?