Not sure if I agree. I think I get what you are saying; for example, Bill Clinton may not hold even liberal political ideals as principles -- he'd happily sell socialism out if he thought it would benefit him personally -- but he holds to the principle that the highest good is whatever benefits Bill Clinton.
Yet I doubt if people like him could express such a "principle" in words even if he were honest enough to do so. If somebody asks me MY principles, I can right down a list. What would X-42 be able to write? His selfishness is not some well-thought out ideology -- it's crass & childish. If Bill Clinton has guiding principles, then so does a tomcat, and the whole term ceases to even be meaningful.
Bingo! It has become a throw-away "feel good" pious term. Instead of talking about my "principles," I simply state what I think is right and what I think is wrong.