Well, uncomputable is a whole lot worse than approximating due to computational limits. You can't even generally solve the problem with unbounded resources, the best you can hope for is in some narrow domains of application.

If you make it much broader, you are guaranteed halting problem type situations where you won't be able to consistently assign preferences.

Theory of values (i.e. model of how people do or should value or decide things) very interchangable with what have you. First approximation meaning that I know you're keeping the math simple, so I don't expect you to delve too deeply into exactly how you should value or prefer things in order to achieve goals more effectively, including details like human cognition limits, faulty information, communication, faulty goals, and the list goes on.

I just feel that talking about Bayesian decision theory as the right way is reasonable, but it's more the beginning of the story, rather than the end.