Yes, decision theory has been floated as a normative standard for human rationality. The trouble is that the standard is bogus. Conformity to the full set of axioms is not a rational requirement. The Allais Paradox and the Ellsberg Paradox are cases in point. Plenty of apparently very intelligent and rational people make decisions that violate the axioms, even when shown how their decisions violate the VNM axioms. I tentatively conclude that the problem lies in the axioms, rather than these decision makers. In particular, the Independence of "Irrelevant" Alternatives and some strong ordering assumptions both look problematic. Teddy Seidenfeld has a good paper on the ordering assumptions.
I think we should stop talking about utility functions.
In the context of ethics for humans, anyway. In practice I find utility functions to be, at best, an occasionally useful metaphor for discussions about ethics but, at worst, an idea that some people start taking too seriously and which actively makes them worse at reasoning about ethics. To the extent that we care about causing people to become better at reasoning about ethics, it seems like we ought to be able to do better than this.
The funny part is that the failure mode I worry the most about is already an entrenched part of the Sequences: it's fake utility functions. The soft failure is people who think they know what their utility function is and say bizarre things about what this implies that they, or perhaps all people, ought to do. The hard failure is people who think they know what their utility function is and then do bizarre things. I hope the hard failure is not very common.
It seems worth reflecting on the fact that the point of the foundational LW material discussing utility functions was to make people better at reasoning about AI behavior and not about human behavior.