You can construct a set of values and a utility function to fit your observed behavior, no matter how your brain produces that behavior.

I'm deeply hesitant to jump into a debate that I don't know the history of, but...

Isn't it pretty generally understood that this is not true? The Utility Theory folks showed that behavior of an agent can be captured by a numerical utility function iff the agent's preferences conform to certain axioms, and Allais and others have shown that human behavior emphatically does not.

Seems to me that if human behavior were in general able to be captured by a utility function, we wouldn't need this website. We'd be making the best choices we could, given the information we had, to maximize our utility, by definition. In other words, "instrumental rationality" would be easy and automatic for everyone. It's not, and it seems to me a big part of what we can do to become more rational is try and wrestle our decision-making algorithms around until the choices they make are captured by some utility function. In the meantime, the fact that we're puzzled by things like moral dilemmas looks like a symptom of irrationality.