Sorry I don't think I made my point clearly enough. I accept that we can talk of ethical preferences, but that is not necessarily the end of the story. So kippers vs eggs, my preference is one that relates to taste; which is mutable and personal. However there are other preferences where one preference is better than another. For example; if I have an aim (x) and two possible ways to attain it (f and p) then I can compare f and p to see which best attains x.
No preference is inherently
better than another. A preference is only better than another if it helps you achieve your aims better. It is not inherently better to "behave in a manner which benefits me most", it's only better if benefiting yourself the most is your aim. It is not inherently better to "flourish as a human being" either.
People seem to have a tendency to assume that subjective things are worthless. I don't really follow this line of reasoning.