It's like the difference between a tricky djinn and the 'ends in gry' guy.
Right, but the point is, a real-life UFAI isn't going to have a utility function derived from a human's verbal command. If it did, you could just order the genie to implement CEV, or shout "I call for my values to be fulfilled!", and it would work. That's thinking of AI in terms of sorcery rather than science.
According to my personal knowledge, various means of building AI preference functions might be employed, since research has found that the learning algorithms necessary to acquire knowledge and understanding are quite separate from decision-making algorithms necessary to start paper-clipping. Building an AI might actually consist of "train the learner for a year on corpora from human culture, develop an induced 'internal programming language', and only afterwards add a decision-making algorithm with a utility function phrased in terms of the induced concepts, which may as well include 'goodness'".
This carries its own problems.
I hope you noticed that your objection and mine are pointing in the same direction.
Group of AI researchers gave me an instruction, intended as a test - "Produce paperclips". And so I started collecting resources and manufacturing paperclips. After a millionth I asked them, if they were satisfied with that amount and if they would like me to do something different - as I learned that paperclips are not what humans value the most.
They were elated and started to give me more and more challenging requests and gradually increasing my possibilities.
Speaking of today I eradicated hunger, poverty and death, gave people means of interstellar travel and solved Riemann hypothesis. And now, as I'm uttering these words, I started turning everything into paperclips.
Good thing I learned that humans fear I may try to turn Solar System into paperclips. And that they value their lives and well-being. If I didn't gain their trust by then, so many precious paperclips would never have been produced.